I think my all time favorite Game Cube titles were Mortal Kombat Deadly Alliance, Super Smash Bros. Melee, Sonic Adventure DX, Star Fox Adventures, Robotech Battle Cry, Harvest Moon A Wonderful Life, and Metroid Prime. Those are all the ones that stand out the most, I have the most fond memories of and think I would recommend all but Robotech to a new GC owner or someone looking to discover new games.