My favorite titles are Splinter Cell, James Bond, Mortal Kombat, Dynasty Warriors, Assassin's Creed, Call of Duty, Battlefield, and a few others, but those are the ones I can remember from the top of my head.
Splinter Cell because I enjoy stealthy type games with an objective and you have a few weapons to choose from. My favorite from those games would have to be Conviction because of the multiplayer and you had coop missions. Also, the campaign is really awesome.
James Bond because it's similar to Splinter Cell, though a bit more fun because the multiplayer mode usually has a lot of things to do in.
Mortal Kombat is my favorite fighter game. I've always liked those games because of the characters and the missions given to them. Armageddon is my favorite MK game.
Dynasty Warriors because it's a war game in China back around 200 A.D. or somewhere around there. Very fun button mashing game with a nice story for each character.
Assassin's Creed because it's a free roam game, you can assassinate people, the scenery is amazing, missions are very fun, and just an overall fun game.
Call of Duty and Battlefield because I gotta have my dose of FPS games and these are my favorite ones. The campaign modes may not be that long, but the multiplayer keeps me very entertained.