Crysis 3: The bow. That thing is so damn OP. You can kill EVERYTHING with it. Except maybe the final boss. Even the TOUGHEST 'regular' enemy you see, you are able to take down with 2/3 arrows that you can retrieve. Plus you don't uncloak.
Bulletstorm had some nice weapons, but i can't really remember details.
Bioshock infinite. The sniper rifle and shotgun are awesome. Those were the two guns i had with me for 90% of the game. You barely need upgrades.
Far Cry 3; Silenced sniper rifle. Take out an enemy camp from across the other hill while no one sees you. Yes please.
Battlefield 3: M5k for CQB. Deadly, accurate and fast. Just how i like it. The M98b sniper rifle. One shot kills baby!
As you can see, i am a fan of stealth.
Don't get me wrong though, a Fat Man is pretty funny. I just never used it that much since i didnt have infinite nukes.