These may not be the "Top" ten, but they're the ten I could think of:

10. Your game stack has more games you've started than you've finished
9. You've never pre-ordered a game - or - you pre-ordered a game and forgot to pick it up
8. You don't know the meaning of the word "Fanboy"
7. You've bought, played and finished a movie/TV show/anime tie-in game
6. You've never conveniently gotten ill when the latest GTA/Halo/Final Fantasy came out