Mine has to be Dragon Quest: Rocket Slime, a DS spin off of the Dragon Quest series that sees you playing as a slime operating a tank and rescuing the people from your town. You run around the overworld, collecting items to use as ammunition and saving money to upgrade your tank. The art and music are just as great as you'd expect from the Dragon Quest series. It made fantastic use of the DS's dual screens. It's also written for a younger audience, so a lot of it is just really silly and fun! Try it out for sure, I'm so sad there's no sequel :(
Vectorman for Sega Genesis is one of my favorite games on the console but whenever it's brought up it is almost exclusively known as just another obscure mascot platformer and it's even been declared a knockoff of DKC just because both use pre rendered graphics. The sequel is also good.