Get digitized! Seriously!
Tron 2.0 is a smart, unique FPS set in a beautiful glowing world. You should probably play it.
The gameplay carves its own niche with an RPG flavoured inventory and leveling system, which manages to add a dash of strategy without slowing down the action too much. Tron 2.0's weapons have some balance issues--the upgraded disc, once acquired, is the virtual death-dealing implement of choice--but the other tools of digital destruction are weird enough to warrant some experimentation just for the heck of it.
The single player end is held together by a proficient storyline with enough nerdy and self-referential humour thrown in that you'll know that it doesn't take itself too seriously. Multiplayer's bland, but the campaign's good enough that no reasonable player should mind deficiencies on that front.
Tron 2.0's a few years old now, and it still looks pretty and plays well. Highly recommended for shooter aficianados.