What's your favorite game you never hear anybody talk about?
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 :(
Jump Ultimate Stars for DS, it is not only my favorite game for the console, it might as well be my favorite game ever.
To be fair I would not say it is like nobody plays it at all, but certainly it is on the low radar and this game would have been lower on the radar if it wasn't for piracy and because thank God the DS is retrocompatible.
Hotel Dusk 1 and 2 gets a honorable mention as well.
Jump Ultimate Stars was huge among the kids in my high school. I probably wouldn't have heard about it if not for the big anime geeks. The pixel art was great, too. Really found a way to mix the different series' styles.