IMHO, Rocco's has the best cheesesteaks in Collegeville. They also make pizza steaks, and have a yummy chicken steak. Of course they have a large variety of pizzas as well. I'm not a pizza person but if it comes from here i'll eat it. Their BBQ chicken pizza is my favorite (warning: has hot sauce on it).
They are pretty popular and often busy, so the only real downside is that you might have to wait awhile to get your order especially on weekends. Also it is dine in or pick up only, no delivery.