Excluded: Arcanis (lol, see sig)
Runner-up: Forgotten Realms (Specially a Waterdeep campaign)
Some people may disregard my favorite because I contribute to Arcanis products, but in all honesty the Forgotten Realms was my #1 world for a long time, yes even after we released the first incarnation of the Codex Arcanis. But as I got to know the world more and more, I began to see how dynamic it was. It’s a world filled with so many realistic conflicts; geopolitical, religious, racial, and even personal character conflicts. Just the worlds belief system has given me more than enough martial for a home game (Gods don’t have alignments, churches have alignments… mortals have developed good and bad interpretations of the gods, and some interpretations are even considered Heretical…) It’s a captivating world filled in with shades grays , a world where being a hero is never easy.