Requiem - Avenging Angel
This is a shooter that can best be described as Jedi Knight meets Quake 2. You play an angel that has to travel through heaven and hell to return to earth, where you must defeat some sort of cult or something. I honestly can't remember the plot but that's not really important. What IS important, is that this is a decent quake-like shooter where you can do totally crazy, biblically awesome stuff. Things such as: Turning your foes into pillars of salt, possessing powerful enemies, bullet time, or literally boil an enemy's blood until they explode. Jedi Knight's force lightning has got nothing on Requiem. Thanks to the quake engine and some decent animations, the game has aged pretty well (or it had about 2 years ago, been awhile since I played it), but finding it now is difficult. Unfortunately Requiem was released not long after Half-life, and it fell into obscurity quickly.
Edit: I just saw that a couple people mentioned Oni as well. It probably has the best hand-to-hand combat system I have seen yet. There is a huge selection of moves, and it manages to stay intuitive and cinematic while still being extremely challenging. This video show the gameplay pretty well, despite the annoying introduction: http://www.youtube.com/watch?v=jjLDz...eature=related
Also, the lead is an actual strong female character, instead of another Lara Croft clone.