I'll play pretty much anything except 3e/3.5. I've been there, done that for the last 8 years, and its just not a satisfying play experience to me.
I'd run 1e, 2e, or 4e. I don't think there is anything that could entice me to run 3e/3.5/Pathfinder again- I really disliked prepping and running it. I'd probably run OD&D and Basic D&D, but I just haven't had much experience with them, so thats a harder call to make.