I'll take Agent J
Unlimited alien tech at his disposal(guns, shields, bombs, flame resistant gear, supersonic cars/jets/boats/spaceships, death rays, etc.).
Goons/Snitches on standby(Frank the Pug, Worms, Jack Jeebs, the entire Arquillian race that can mimic humans with exosuits).
Ability to time travel(MIB 3), so if shyt goes wrong, he can go back and fix it.
And of course, neuralyzers, which in itself is op'd. One flash to the opps, and they won't know what the fukk's going on or why they were trying to kill in the first place. In fact, J will give them a new memory that they now work for me.