I'm going to say either Killzone or Borderlands.
Killzone is just an awesome futuristic setting which I love, with realistic (somewhat) guns and vehicles that are all super fun to fire and use. The story is okay and all, but the real meat is where the action and the focus on detail.
As for Borderlands, the setting and characters are fantastic, as well as the unique way you get new guns. Having the possibilities of guns basically endless is great because it will always let you find a better gun than your last one. It's also a real watercooler game, being able to talk to your friends when you next see them and describe the new assault shotgun you found, or listening to a friend tell you about the epic new sniper rifle he got that blows the top halves of enemies off.
Killzone is just an awesome futuristic setting which I love, with realistic (somewhat) guns and vehicles that are all super fun to fire and use. The story is okay and all, but the real meat is where the action and the focus on detail.
As for Borderlands, the setting and characters are fantastic, as well as the unique way you get new guns. Having the possibilities of guns basically endless is great because it will always let you find a better gun than your last one. It's also a real watercooler game, being able to talk to your friends when you next see them and describe the new assault shotgun you found, or listening to a friend tell you about the epic new sniper rifle he got that blows the top halves of enemies off.