SharkLord
Smash Hero
I don't know too much about TF2 or Half-Life, but I think they'd be pretty cool. I actually had a vague idea about a -esque team of Scout/Heavy Soldier, though I'm not sure that's what we'd actually get.What's everyone's opinion on Valve representation? Even as a Mii costume or Spirit or even a full fighter. Whatever you think works.
Gordon Freeman or Scout/Heavy could suffice for any of those roles. Unsure about Portal, though it would make for a good Gunner costume.
Something I find interesting is that Half-Life is quite an influential series, but doesn't get much attention in the Smash community, and I think what little discussion it does get stems from that one fake leak. TF2, on the other hand, soaks up all the Smash discussion in terms of Valve reps. Strange, isn't it?