I used to pretty much play all RPGs vanilla, mainly because I was too lazy to go through setting up the mods. But it's a lot easier nowadays, and I've recently started a Fallout 3 campaign with the FWE mod package, and it is amazingly more immersive. Once I've finished this playthrough I'll probably look into the JE Sawyer mod for Fallout: New Vegas. That or something with Skyrim. Or maybe I'll finally do all that restored content mod for Knights of the Old Republic 2, because even the original (clearly incomplete) game was fun for me, and restored content just sounds fantastic. For RPGs in general, though, I think I'll at least play through the vanilla game once before overhauling it and changing it. I want to get a feel for how the makers intended it to be on release, before I throw that out the window and turn it into a different game.