In terms of downloads, there's Wario Land 3 (Fantastic game), Ikachan, VVVVVV, Mole Mania, Soul of Darkness (A surprisingly good Castlevania knock off), Amoebattle, The Legend of Zelda: Link's Awakening, Harmo Knight, Mighty Switch Force 1&2 and Liberation Maiden.
In terms of cartridges though, there's the Megaman Starforce series, Kid Icarus Uprising, the Mario & Luigi series from Partners in Time, Bowser's Inside Story, and Dream Team, Okami Den, Radiant Historia, Rune Factory 3 (Love this game), Super Robot Taisen: Endless Frontier... Lot's of games.