Hmm, I'd recommend Condemned 2, and Devil May cry 4.
Condemned 2 was superb, imo. Dark, twisted, gory, scary - one of those few games you actually pickup and just 'play til you finish'. Got a lot of good elements all rolled into one.
DMC 4, looked unreal. Boss fights are different all the way through, and some of the combos you can pull off - particularly as things gets harder and you unlock different weapons/abilities - are awesome, and keep things changing all the time.