There are a lot of D&D campaign settings out there, both "official" and otherwise (not that the distinction matters all that much). I thought it might be fun to briefly touch on a few that I think are pretty unique, and which appeal to me enough personally that I would most love the opportunity to use them, either as a DM or a player. Please keep in mind that I haven't actually read the books for most of these settings, so a lot of this is based on second-hand information, reviews, etc. This is more about what I want to get into than what I've already gotten into.
For the sake of simplicity, I've kept the list narrowed down to settings that have been officially published by TSR, Judges Guild, or Wizards of the Coast OR that I personally own as a book or PDF (in other words, LotFP stuff). There are a ton of interesting and wonderful campaign settings out there in the form of either publications I haven't bought/read yet (like Yoon-Suin) or series of blog posts (Centerra from Goblin Punch comes to mind). This is far from an exhaustive list of either stuff that's out there or just stuff I like. This is just:
THE TOP THIRTEEN CAMPAIGN SETTINGS THAT ARE THE MOST INTERESTING TO ME AT THE MOMENT (insert fanfare here)
I mean, other than Blackmoor, this is about as classic as it gets, right? I imagine playing in Greyhawk would be like observing Gygaxian D&D, with all its cool/weird/funny monsters and magic items and other little details, in its natural habitat. I know that Greyhawk, like the Forgotten Realms or Dragonlance, could be considered either too boring or too well-trodden by many, but for whatever reason I still find what some have dubbed "generic" fantasy interesting in its own right...when done well, of course. (Notice that, although I don't exactly hate them, the Forgotten Realms and Dragonlance didn't make this list.) Besides, much of what we consider generic now was pretty unusual back in the day, right? And some things in Greyhawk are unusual even by the standards of the now-saturated market of fantasy fiction; examples include science fiction stuff, Alice in Wonderland-type stuff, the Black Reservoir, dinosaurs, and a big stone head that people still seem to speculate about to this day.
Dungeonpunk, Warforged, and Artificers...I had some brief experiences with material from Eberron during many a D&D 3.5 game in college, and these glimpses certainly intrigued me. As much as I like low-magic dark fantasy, I also think that high-magic fantasy settings that blur the line between magic and science can be a lot of fun, too. Eberron strikes me as the kind of place where the stuff I like from JRPGs like Final Fantasy can mix well with D&D...hopefully without the stuff I don't like.
11. Dark Sun
Conan meets Mad Max meets Dune. I mean, come on! It doesn't hurt that this is one of the most positively regarded of the official D&D settings, as far as I can tell. I like the concept of the use of magic actually hurting the ecosystem. I hear the monsters rock, too.
10. Wilderlands of High Fantasy/City State of the Invincible Overlord
This would probably be higher on the list if I knew more about it. This setting devised by Judges Guild seems to come highly recommended by anyone who's heard of it, so color me intrigued. Besides, I could always use more OD&D material to read!
Honestly, the Gothic/Hammer Horror, always-Halloween, Castlevania-esque, cheesy-yet-spooky kind of setting just really appeals to me. The isolated demiplane segmented by evil fog reminds me pleasantly of Demon's Souls and Silent Hill. I've heard Strahd can be a great villain if you play him right, and some of the other major NPCs seem interesting. My favorite detail of the setting (which I've heard in passing and have yet to verify) is that something restores the spells of clerics each day, but it sure ain't one of the intended gods. My only major misgiving is that I've heard a lot of Ravenloft material is pretty railroad-filled, but hopefully that problem could be overcome with a little creativity.
You're already dead - make the most of it. Again, very Demon's Souls, with a touch of Wraith: The Oblivion (which I haven't played, but which fascinates me as a concept). Seems unique. Considering there was only one book produced, it should be an easy setting to read up on, too. Honestly, the rarity and obscurity of Ghostwalk are attractions for me. Plus, I'd like to see ghosts presented with more variety and nuance than the typical Monster Manual gives them. See The Hell House Beckons for great examples of creative D&D ghosts, in case you're wondering what I have in mind.
Ah, Sigil - a whole city that's basically the cantina from Star Wars or the Restaurant at the End of the Universe, but in the middle of the D&D planes instead of a galaxy far, far away, but which also functions as a massive portal network. Oh, and it's shaped like a torus. And it's at the top of a spire that everyone insists is infinite even though it looks pretty darn finite (but still big). And the residents have some really distinctive slang. And there's the Lady of Pain. And there are modrons! I can't believe I haven't gotten into this one already. I really like the concept of a cosmos in a fantasy universe that differs significantly from the whole stars-and-planets-floating-in-empty-space thing that real life has going on. Planescape seems to just take every gonzo aspect of every major D&D setting and get it all to fit in the same screwball universe, and it even seems coherent if you squint a little - not that fantasy needs to be so mundane as to be coherent, of course.
D&D! IN! SPAAAAAAAACE! Except it's not really space so much as a quirky fantasy version of space, with spaceships that look and act like regular ocean-faring ships. It's actually pretty reminiscent of the old-fashioned "Celestial spheres" model of the universe, except instead of there only being a single crystalline sphere, beyond which lies Heaven or God or the primum mobile, there are multiple crystalline spheres containing different worlds and separated by a type of outer space different from the outer space inside the spheres. As with Planescape, I find the cosmology very compelling, plus the idea of space pirates looking and operating like regular pirates is charming. The monsters and intelligent races of the setting seem pretty eccentric, too, like the musket-toting hippo-like giff and the bizarre, horrifying neogi. Spelljammer just seems like the kind of setting that would lend itself well to mixing in science fiction based on fun, outdated concepts like luminiferous aether or Planet X or Martian canals or Venusian jungles or Moon Men, or the sun going out like a candle.
I've heard that Blackmoor takes place in the far past of Mystara, so I'm lumping these two together for now. Many of my thoughts on Greyhawk also apply to Blackmoor (with Gygax swapped out for Arneson, of course), plus Blackmoor seems to have plenty of cool oddities of its own, including a stronger mix of fantasy and SF. Oh, and Blackmoor almost seems like the "lost" original D&D setting that people new to the game don't hear about, so it interests me for both its historical value and its surprising obscurity. Meanwhile, Mystara is pretty much the official setting for Basic D&D, and it has just about anything I could want from the typical D&D setting crammed into one world: fictionalized and magical versions of all kinds of different real-life cultures throughout history, a Hollow World, dungeons and monsters galore, and a path to immortality available for those strong and determined enough to seek it. It's the good kind of fantasy kitchen sink.*
4. Lankhmar/Nehwon (based on the stories of Fafhrd and the Gray Mouser by Fritz Leiber)
It's an official campaign setting based on one of the most important literary series in ye olde Appendix N. Enough said.
I have a lot of thoughts and opinions on Geoffrey McKinney's Carcosa, and in a lot of ways my reception of it was, shall we say, mixed, but I won't get into that now.** What I can't deny is that Carcosa is absolutely brimming with awesome stuff: mummy brains, ridiculously powerful (and just plain ridiculous) space alien technology, mutant dinosaurs, psionic power rules that don't intimidate me out of ever trying them due to over-complexity, a hex crawl with some truly odd locations and encounters, OD&D/LotFP stats for classic Lovecraftian monsters, amusing/creepy mutations, crazy rainbow people, and a world that didn't so much fall from grace as simply never be graceful in the first place. To me, Carcosa is a fascinating mix of bleak and silly, and I can't help but be drawn to something so outlandish. It doesn't hurt that most of the setting details are imparted though game mechanics, tables, monster/item/hex descriptions, etc. instead of long, boring historical overviews.
2. Empire of the Petal Throne/Tékumel
This is probably the only official (well, okay, semi-official) D&D setting that is actually as rich, complex, deeply thought out, and internally consistent as some of the best F&SF universes like Lord of the Ring's Middle-earth and Dune's Imperium...or at least that's what all the Tékumel fans on the internet seem to say. Based on the language M. A. R. Barker created for the game and all of the historical research that went into crafting the setting, I can believe it. There are so many details that make me curious, too. Why and how was this planet separated from the rest of the universe? Who or what are these strange gods the inhabitants are basically forced to worship? What made this highly regimented society the way it is? What is there underneath these layer cake-like cities for us to plunder and kill? I love how this is basically a science fiction setting that looks like a fantasy setting to its inhabitants. Arthur C. Clarke would be proud. (Actually, I wonder if he was familiar with Tékumel at all.) This seems like one of the few settings with a long, drawn-out backstory that might be genuinely captivating to read, since it's so weird and so intricate.
1. Earth (Lamentations of the Flame Princess/Castle Amber/Masque of the Red Death/A Mighty Fortress)
James Raggi has already made some compelling arguments for setting a D&D campaign on good ol' planet Earth. It's not like the concept is foreign to D&D, since Clerics originally used crosses as their holy symbols and several D&D books have involved Earth in one way or another. I like the idea of being able to browse real-world history books for setting information, although I would probably play fast and loose with historical accuracy to some degree, since I'm no expect on early modern England or whatever, and besides, anachronisms can be fun. Still, setting a game on Earth can ground things a bit, making things more familiar and less abstract. This has the dual benefits of giving the players' actions and choices have more predictable consequences ("No fair! If I knew that all snakes were books in this setting, I wouldn't have cast Disintegrate on the naga!") and making magical and otherworldly elements have a greater impact ("William Shakespeare is an aboleth! Run for your lives!"). Earth is chock-full of strange places to explore, too. I bet the Paris Catacombs could make for an awesome megadungeon. They say truth is stranger than fiction. Let's test that hypothesis.
Honorable Mentions: Qelong (I wasn't sure if this should count as a separate campaign setting), Thieves' World, Birthright, Council of Wyrms, Dragon Fist, Jakandor, Kingdoms of Kalamar, Mahasarpa (online supplement for Oriental Adventures), Nentir Vale/Points of Light, Pelinore, Ravnica, and Thunder Rift.
Anyway, please feel free to correct me if I got any details wrong, berate me about how stupid the order and contents of my list are, or tell me about any interesting settings I missed.***
*Perhaps much of what I've written above seems like a defense of
"standard" or "generic" fantasy, and to some extent I suppose it is,
since not everything that people put in those categories has lost its magic
for me yet (ha). However, for a campaign setting to really impress me,
it has to strike me as unique, original, unusual, or just plain crazy. I've come
to absolutely love D&D material that breaks out of the conventions
of the game and just goes nuts, for many reasons: it keeps people on
their toes, it tends to be more flavorful, it encourages creativity, and it shows that "fantasy"
is a wide genre that encompasses so much more than just dragons
and elves. Products for Lamentations of the Flame Princess, for example,
are like a continuous breath of fresh air (or maybe I should say rancid
air, considering the deliciously morbid and horrific themes), and the
OSR is a well of inspiration that never seems to run dry for me. With a
few exceptions, the oddball settings tend to interest me the most.
**I know I'm really late to the party on this one, but I'm thinking about doing a detailed review or blog-through of Carcosa at some point, like what I've been doing with Holmes Basic D&D (although maybe not as in-depth, for fear of taking forever to get through the whole thing). There's just so much strangeness to talk about, in terms of both setting and game design. For now, let's just say that I like Carcosa quite a lot overall, as its position on the list above indicates, but a lot of individual aspects of it don't quite make sense to me.
***Hopefully I can add The Driftwood Verses to this list someday.
Edited on June 18 to add Jakandor to the list of Honorable Mentions.
Edited on May 27, 2019 to replace one entry with Lankhmar, slightly reorder the list, and add Thieves' World, Kingdoms of Kalamar, and Ravnica to the Honorable Mentions. (I guess the "Right Now" in the title of this post really means "Over a Period From 2016 to 2019." I didn't see the point in putting up a whole new post on this subject when my opinion has changed only slightly.)