Im a big fan of a large experience table a-la AD&D. I haven't played any D&D in about 10 or more years, sadly, but I do remember its biggest appeal being I could do, literally, what I wanted with my character and not have him/her locked into any one role and I could look down 5-10-20 levels ahead to see what route I wanted to take as opposed to be locked into it. I could strengthen certain things and keep certain things as they were. Although I almost always leaned towards an intellectual dual-wielding Rogue/Fighter type character just because I love stealth-type classes.