Rainbow Six 3 PC

It has awful AI. And that's a HUGE problem considering that it's such a huge part of the game (it is squad based after all... if it was just a solo shooter, like halo, it wouldn't really matter to me, but in R6 you kinda need good friendly AI).

UBI Just fucked it all up. And they made it so hard to mod, there's barely any community for the game (R63 would have been massively improved by the mod community if Ubi hadn't taken a dump on UE2).