Half-Life 2's Gravity Gun, I remember playing with the groundbreaking physics for an hour before even using it as a weapon back in 2004. Then when it gets super powered inside the Citadel, there was nothing like killing a man by throwing his friend at him so hard and fast that it breaks every bone in his body.
Half-Life's Crossbow, Snarks, Gluon Gun, and Tau Cannon also deserve recognition.
Bloodrayne's Dual Arm Blades. Highly impractical looking, but when you dice up nazis into nice little pieces while in slow and super fast motion, it's as beautiful as ballet.
The Ultra-Batclaw and Zip-Line from the Batman: Arkham Games combined with an enemy near a ledge.
Half-Life's Crossbow, Snarks, Gluon Gun, and Tau Cannon also deserve recognition.
Bloodrayne's Dual Arm Blades. Highly impractical looking, but when you dice up nazis into nice little pieces while in slow and super fast motion, it's as beautiful as ballet.
The Ultra-Batclaw and Zip-Line from the Batman: Arkham Games combined with an enemy near a ledge.