The Blaster Launcher from UFO: Enemy Unknown.
You may not know it, but this game is awesome. And so is this weapon. After all the hard work killing enemies with vastly superior weapons and equipment, you can finally get your hands on their weapons, this included.
Basically, it's a rocket launcher, but with a massive radius, it can take a house down with one shot. Also, it's very damn accurate, and best of all, you can set waypoints with it. So, you can make the missile go across the whole map and into your enemy's face if you want. Basically, it's a nuke that you can shoot to anywhere with any character, okay?