Actually... Which system, QAGS, BHB, or otherwise, would be best for a Dungeon-Crawlie + Open-Worldy type-game with custom races and classes? I know that Dungeons and Dragons works sometimes, (I've read a book about orcs in Kingdoms of Kalamar which really explores the things you can do with classes/races.) but I have no idea which edition to use, and I'm not sure I could handle fotzing around with all those numbers without a lot of things messing up. (Especially if I get to any of the parts with exponential powers.)
Basically, I'm looking for something with freedom, (but not too much freedom, because there's just something cool about having a ruleset.) where roleplaying can be a higher focus point, and where you can create all manner of custom shit. BHB looks pretty good, as far as the right amount of freedom goes, but, from what I've seen, it's really lacks the inherent racism and classism that you can have in a D&D character sheet.
Definitely need some help and advice from more experienced system gamers.