I'm a huge fan of the factotum. It might be my absolute favourite published class!
Not too many, I don't think. In fact, I can only think of the geoccult nymph pool, the dungeonjammer's capstone, and the 5th level graft 'noble blood'. And maybe shenanigans involving silver transformers. It's a pretty awesome open-ended effect, which is why I like it so much. It's both freeform and also well-regulated; to me, it pretty much symbolizes what D&D should be about. The player says, "I want this to happen", and then the DM and the player work to figure out how to make it so.There are an awful lot of ways to get the effects of a Wish spell, huh...