X1: Wolverine, Magneto.
X2: Pyro, Iceman.
X3: Colossus.
I actually think the X3 scene might be her best power scene of the trilogy, If it was made to be a "Rogue moment". They could have the camera showing her skin transform to metal in a close-up, and then she could spend at least some 5 seconds in metal form. She should be the one who touches Colossus, and not him "pitifully" touching her. Also, the effects could be a lot better. It's undoubtedly the worst effect scene of the movie.
Just imagine the X2 scene happening on Rogue's body. It would have been awesome x1000.
One more thing related to Rogue and her powers, I would LOVE if the first X-Men movie followed the original script. Rogue had a much more active role, absorbing Mystique to defeat Magneto by kissing him. Now that would be good to see. Although the movie we got has a beautiful, touching scene when Logan "ressurects" Rogue.