Eberron because it's not the patchwork other settings are. All the countries have relationships to eachother, not just their immediate neighbors, going by 1000 years+. The continent full of dragons? Even when it stays in the background it's important to plots due to their involvement being a clear fail condition (They scoured a continent of civilization once, and aren't going to hessitate to do it again if needed). The actual industry of the world has actual detail and importance beyond just background notes on imports/exports at best. The non-continuity prevents problems like From the Ashes, the Cerulean Storm, the faction wars, or Spellplague from wrecking the setting while simultaneously letting module/novel creators go wild (Want to have a released extra-dimensional beast wreck the world's largest city? Sure, go nuts, it only applies to your continuity anyways.) and letting the player's actions have actual impact. It's not a straightforward fight of "good" vs. "evil" and the DM is free to have virtually any faction be an antagonist, while the majority can also be allies.
Fixed the first sentence.
Eberron is a big patchwork of everything the author seemed to love, that makes no sense at all and just build for the rule of cool. It wants to be everything. Can be fun, but it's too much in love with it's own lore.
The Forgotten Realms can be quite weird too, because everything is possible and that can be really fun. If I'm honest, most adventures are not weird enough and too generic, but
Shadows of Undrentide shows how the setting can be fun and still make somehow sense.