I picked Crowe.
He didn't say any famous lines. He didn't get a sequence. He played no important role. His part of the story consists of having had bad luck. He didn't got to fire a single shot. Probably didn't even got to see any Aliens with his own eyes. He didn't even got a face shot...except when he was dead. His death was not glorious, gruesomely espectacular or even relevant for anyone but Hicks. he just got flung into a wall very hard. his last words were a chocked "OH SHIIT-". he was no hero, no villain, no sidekick with extravagant character and a big mouth. he wasn't exceptional, memorable, outstanding or likable. he was just Crowe.
He was the guy every one of us would be in that situation.