Colosseum, XD, and the Stadium games(but mostly 2) were my favorite. 2's Gym Leader Castle, simple free battle mode and the music won it for me. Coliseum's VS Mode with Mt.battle and Stadium like selection of Coliseums very Pokecup and Primecup Like and story was great. XD is the same, except free battles were a bit more challenging for me, and the Battle Sims are helpful. But I had fun playing all 3