Here's the next wave of fantasy settings I'm commenting on. Probably one more post on this topic too.
Dragonstar: Briefly in the early days of Third Edition D&D, Fantasy Flight Games put out this setting, which was essentially "D&D in space." And I don't mean that in the Warhammer 40,000 sense of having "elves" and "orcs" and "dwarves"; I mean that in that it is literally Dungeons & Dragons in space. On spaceships. Casting spells and everything.
Kinda a fun idea; honestly I was never really sure what to do with it, though.
Urban Arcana: This one is a little iffy; technically it's a d20 Modern setting, not a D&D setting, but d20 Modern and D&D are already essentially the same thing to begin with system-wise. This setting was more explicitly D&D in modern times though; it even has drow fer goodness sakes. For my money, I'd rather play this as a kind of Dresden Files meets Buffy meets Shadowrun.
Sovereign Stone: This setting was most notable for 1) being written by Margaret Weis of Dragonlance fame, being illustrated by Larry Elmore (of all kinds of older D&D product cover artwork fame) and having a pretty nifty new magic system to replace the D&D default.
Sadly, other than that, it fell pretty flat. So the elves are samurai and the dwarves are Mongols... that's not original, that's just swapping one tired paradigm for one that's silly. I bought these books on the cheap from an old Wizards of the Coast outlet store in the mall back when they were closing all those stores, otherwise I probably wouldn't have bothered. Other than the magic system, there's not even anything worth borrowing here.
Northwall: Not so much a setting as the seed of one included in FFG's Darkness & Dread book, which is otherwise a book of alternate rules and GMing advice for running a horror fantasy game. Northwall is a chapter near the end that serves as a kind of mini-campaign setting. As a setting itself, it's not that interesting, original, or fleshed out, although it is kinda nice. The book is really more notable for the alternate rules.
Scarred Lands: Famous for getting a monster book out before the Third Edition Monster Manual was on sale, this setting is kinda interesting. The premise is that there was a war between the gods the titans a la Greek mythology; except that instead of happening in the distant past, it just got over with a few decades ago. The world is still scarred from the conflict (hence the setting name) and it's got a bit of a fantasy post-apocalyptic vibe going through it. Sadly, the setting is difficult to encapsulate in a single product; the Gazetteer being the closest thing to an actual setting book. Rather, it trickled out via various products over several years.
It's got some great things to borrow; tons of original monsters, Hallowfaust, d20 "skaven" and more, but it's a little difficult to run coherently on its own, I think. Plus, it's kinda weird, frankly. And not always in a good way. Too many "out there" ideas rather than a few well developed ones lead to a scattershot feeling setting.
Rokugan: Technically introduced as a D&D setting in the Oriental Adventures product, this was also released as a setting book by AEG as well (I have both.) Sadly, although Oriental Adventures was an easy read, I have struggled to get all the way through Rokugan, even thought the setting appeals to me. It's a kind of sorta ancient China, samurai Japan and D&D all rolled into one. The AEG book starts off with a lot of alternate rules, which have been handy for borrowing, no doubt, but which also make the book extremely difficult to read.