Giantman vs Hulk
So... this should be a pretty good one. The two get stronger and stronger. Hulk's only weapon is physical strike, so giantman grows almost infinatly, but then so does Hulk.
So... giant man kills... Hulks dog (just go with it). Hulky gets pissed... Oh, and Hulk was taking his doggy on a walk in the Sahara dessert.