Perfect Dark - Laptop Gun
We can't begin to imagine how many frags we've racked-up - perhaps rather cheaply - by placing Perfect Dark's Laptop Gun above doors and entrances. Opponents never see it coming - and if they do, you're already planting shotgun shells in their back whilst they attempt to pot-shot your silver stallion. Needless to say, the Laptop Gun was quickly outlawed in our multiplayer sessions.
Unreal Tournament - Redeemer
The biggest gun in deathmatch (if you call it that - it's more like a nuclear warhead with a trigger) unsurprisingly racks up one of gaming's biggest killcounts. Fire up the secondary mode for first-person piloting, drive it to the enemy flag room and watch the m-m-monster kills roll in.