Tomba! on the first playstation. The first game is better than the second, but both are very fun platformers, maybe metroidvania in a way? Since there's some backtracking as you gain new stuff and abilities.
A possibly not very known title from the PSP that's totally worth the time: Kenka Bancho. There's only 1 in the series that was localized in english, which is the one I played and enjoyed it a lot. You're a high school japanese student on a quest to be the ultimate high school badass.
Neither is mediocre, they're possibly just "hidden gems", really.