>>15743147
for games, probably source.
EYE, VTMB, Dark Messiah and some valve stuff all on the same engine. plus, hammer is straightforward.
in a lot of ways I hate it though, about half of the games on source give me a headache, the way it loops audio and freezes the screen when it loads stuff pisses me off, even more so when it does anything related to networking. also, the custom model, texture and sound formats are annoying.
serious engine would also be a good contender though.