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 :(
Whoooooooa, now you’re really taking me back. I only had the Shareware version, so the full version with all the fighters was something I lusted after for ages, but never actually got. Megarace is another one from this era that stands out, though I don’t think it was a particularly great game.