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 :(
RAMPART. An Atari Games arcade game with strong strategy and puzzle elements. Very difficult in the arcade, and has like 12 home ports, including one as late as the PS3. A lot of Atari arcade games from that era aren’t talked much about these days, but with Rampart it feels especially egregious.
I could mention lots of games here. I love lots of overlooked games. I even like Athena, of all things, and I am fully aware of its many flaws.