I almost forgot about Drebin. Almost. One of the more personable characters in the game to talk to Snake, he offers himself up as a gun launderer by removing the ID chips from weapons, which allows anyone (mostly Snake) to use them. Drebin is one for showmanship, who has a knack for magic tricks and a very sly demeanor.
He supplied Snake with the weapons he needed and rescued his new client from certain danger on more than one occasion. Plus the dude has a pet monkey that smokes and drinks soda. How much cooler could he possibly be?
Image Source: Metal Gear Wikia