lessee...
Subject something-something(portal). A stupid amount of time messing around with the ASHHPD to save his life has made him HANDY with the thing.
Gordon Freeman. badassitry, stupid amounts of intelligence, and the zero-point energy gun.
Daniel Garner(painkiller). unlike other shooter heroes, he had to survive pure undiluted action. also, he has a gun that fires shurikens and lightning.
The Hulk. the more people are hurting him, the more angry he gets. the more angry he gets, the more strong he gets.
Myself, i'd be throwing nuklear grenades. what? those totally exist as much as all the above mentioned do.