It's funny, even though I spent a ton of hours playing Pokemon, it isn't really even close on my personal top ten list. I think in general I played
all of my portable games to death, even stuff like Finding Nemo on GBA, etc.
Pokemon just had the most things to keep me occupied (Completing the HG/SS Pokedex, getting a black five star Trainer Card, etc.), and I've just always had a desire/tolerance to play portable stuff to a pulp more than console games.