I realize they've probably fought a dozen times over the years, but I am interested in what you think would happen, not the latest writer at Marvel. So consider this matchup:
On the one hand, Iron Man has, over the years, become one of the main powerhouses of the Marvel Universe, occasionally rivaling the power of Thor and Hulk. He wasn't always that way, though. For many years Iron Man ran the risk of burning himself out at anything approaching maximum power and wasn't anywhere close to god-like ability. I guess a vast fortune and a top-grossing movie franchise can really help a guy out.
Colossus has such a lower profile, I bet most people don't even put them in the same league. But Peter's incredibly strong and incredibly tough. He's gone toe-to-toe with the heavyweights as well and come out looking pretty decent.
So the fundamental question here is, does organic armor trump manufactured armor? Is a guy in a suit better than a guy who IS the suit?
Sound off in the comments and let us know how you feel!