Definitely Foundry Worker Aldridge. Firstly, Support Specialist is my favorite perk in the game, and a guy with a welding mask just seems suited to that perk. Aside from that, I absolutely love his description. Almost like he's being casual about a specimen breaking into the break room; "Well... seems the breaks over, time to kick some ***."
It's also a bit of a bonus that he isn't used too terribly often, so it gives me a little more identity when people see me running around, or see the portrait of a guy with the welding mask.