I selected the Terminator from Judgement Day (who is programmed to protect this group) because he is nigh indestructible. Running into a press or a lava pit in a post-apocalyptic landscape is pretty remote. The Terminator has built in long and short range scanners as well as intimate knowledge of all technology. He can go toe to toe with any group of humans he runs into and will most likely win. He's also a power source in a pinch!
His intellect is so great he can instantly realize how anything works. He is the ultimate survivor with the exception of hunting which I will address with my next pick. He can kill with a thought and reads minds. Quite handy when running into roaming packs of humans.
He's already proven he can survive in the barren outback. He can out think gangs and pick them off one-by-one. He can also survive in an urban setting if needed. Dundee also has a penchant for recruiting help from formerly hostile groups. If he is not successful, then the Terminator and Paul Atreides will dispatch them quite easily. Lives by his wits and is a great hunter which helps the team tremendously. His only weakness is seeing ladies in skin tight, one piece bathing suits!
What do I bring to the table? While others who have submitted lists may be cowering in their happy place when the proverbial crap hits the fan, like this:
I am proficient in rifle (steel or scoped sights, training as a sharpshooter), shotgun, pistol, longbow, compound bow, knives and axes. I am by no means anywhere near a Punisher or Arsenal level of proficiency. I am also knowledgeable in hunting, fishing, hiking and camping. I can at least help the team. Face it, without some expertise most others would be dumped off the four person team!