there actually is a combat evolved port on pc i think
Also Halo 2.
No Halo 3 or anything subsequent though.
Which is a shame really, at least as far as Halo Wars goes, because that was a game that really would have benefited from being on the PC.
RTS's are fun, but the controls were so awkwardly limited on the Xbox. It really needed a PC with a keyboard so you can have keybinds.