I'll take a Colt M4-A1 with optional silencer, scope, and grenade launcher attachments.
Actually no. I want this:
Zero-Point Energy Field Manipulator With Organic Management Capabilities
What are you guys going to do when I use all sorts of metal objects as shields, throw them at you, and then pull your dead comrades towards me and throw them at you once again? Or I could just use it's main fire mode and hit you so hard that your bones get crushed and die!