If you'e looking for something noticeably different than Greyhawk, FR, or other vanilla settings, then I would advise against The Wilderlands of High Fantasy, Áereth (DCC #35), and Aihrde (Troll Lord Games). All are very good settings but thay're also not much different from other vanilla fantasy settings out there where basic nomenclature is concerned (to wit, you'll see all of them frequently recommended in "Sell me!" threads for vanilla fantasy). Now, if you want vanilla fantasy, you can't go wrong with any of those three settings, and I heartily recommend them all (though I'm partial to the Wilderlands).
If you want something different or non-vanilla, I think that things like HarnWorld (fantasy with a strong emphasis on verismilitude, unmatched in that regard by any other setting currently in print), Oathbound (high level, baroque, fantasy), Shadow World (high fantasy re-imagined, with unusual twists such as humanoid dragons and Evil as an actual entity that dwells in the setting), or The Scarred Lands (post-apocalyptic dark fantasy that takes place after a war amongst gods) will serve you much better. All of these are good, though my personal favorites are HarnWorld and Shadow World.