Food Fight would be at the top of my list. Most of my 7800 collection was purchased years ago when prices weren't so crazy. A few other favorites are Ninja Golf, Rampage, Donkey Kong and Donkey Kong Jr. I have a sealed Alien Brigade that I actually haven't played but I am on the lookout for a loose copy. Lately it's been Galaga for me. Not the best version compared to others but I think it's still fun to play and holds a certain challenge that makes me play it first when I power on the 7800.