depends what kinda style your after? do you have preference on what sorta time frame its set in?
shadow of the colossus is an amazing game, very interesting battles, every battle is a boss battle! check vids of this
metal gear solid series are good, set in modern day war times. Stealthy action adventure if thats your thing, very deep story, almost like watching a film at times. great stuff though.
devil may cry series, challenging games.. fantasy setting, sorta gothic but with guns and swords. big on style this one
god of war is an amazing game too, very well done adventure game. greek mythology, big boss battles, interesting mini battles. the 2nd one is out soon.
prince of persia series, ive only played the first but they all seem to get good reviews, and you can pick up all 3 for really cheap. set in old days, really nice platforming puzzles if thats more your thing.
okami, really good also, very long game which is very zelda style. based on japanese mythology, with really interesting gameplay elements.
these are the cream of the crop i reckon, check them out on ign or gametrailers to get a feel of them