I voted "other/third-party setting," and that setting is Iron Kingdoms by Privateer Press. It is so far removed from D&D that it is almost a game unto itself, which is a refreshing change of pace for someone like me who's played nothing but D&D since 3.0 came out.
Greyhawk and FR seem like two sides of the same coin to me; one side (Greyhawk) is for those DMs who only need a loose framework around which to build their adventures, while the other side (FR) is for those DMs who require a richly-detailled setting populated with a ton of NPCs. Other than that, I really don't see much of a difference between the two.
I initially shunned Eberron as a pale shadow of Iron Kingdoms, but once I read through the book I realized that it was a strong setting on its own. However, if I was going to run it again, there are a lot of changes that I would want to make to the world. Iron Kingdoms is a game I am happy to use as-is, right out of the book.
And it's a gorgeous book, too. Well, two gorgeous books. Something that bothered me about Eberron was the inconsistency in the artwork. Not the quality of the art, mind you, but the style, the look of the world, changed based on the artist. With Iron Kingdoms, there is a strongly-established look to things, and the few artists they have working on the books adhere strictly to that look, so it doesn't look like a mish-mash of different ideas.