Super Princess Peach (DS)

I was thoroughly surprised by this game. My fiancée bought it for me as I was too embarassed to do so myself and it's a solid, fun, challenging game.

I personally find the challenge more evenly balanced than New Super Mario Bros. - had it some of that title's graphical flair and a more toned down colour palette, I would go as far as saying it's the better of the two games.