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 :(
To be fair, I have an installation disk and just copied the installed files and some patches to the deck. You need some special fonts I think. Other than that, it has no copy protection so it runs fine without a disk.
Thanks for the info! Now where did I leave that disk…