Columbo: Because he'll know where the moles are before I even assign him to my team, and find the little clues to prove he's right along the way. We'll find 'em all be lunch.
Chell: Why hike through the caves when we can zip through in handy-dandy portals?
Duncan MacLeod: Certainly couldn't hurt to have an immortal swordsman at the point, could it? If the mole people get a tad stab-happy, no problem. The rest of us scamper backwards for a bit, Duncan comes back, and onward we march.
Virtually any main character from any game ever made: This broad statement represents those in that not-so-elite group that can kill creature after creature after creature without rest or remorse.
Seven of Nine: Borg efficiency at it's finest. Never mind the catsuit (another plus), if anyone can get such an eclectic group to work together, Seven is it. Plus she's good at anything she set's her mind to: that's bound to come in handy. Maybe inject some nano-probes into the portal gun and make it even more awesome.
Seems like I'd be completely unnecessary in this group, but the king of the world is counting on me, so I guess I have to be there.