Collosseum had a pretty interesting story line. Its alot more on its own the the stadiums, but not as much as Xd. Never the less, Collo just had something Xd didn't. I also admit to being a pokeholic! You obtain shadow pokemon who you steal from trainers of the organization chiper, who are closing pokemon;s hearts and turning them into fighting machines. There are total of 48 shadow pokemon to obtain and 'purify' into normal pokemon, along with your two starters umbreon and espeon, and a Ho-oh at the end. I suggest getting a GBa and Ruby, saphire, Fr, lg, or emerald. They were pretty good.