The games that sell in Europe are:
1. Hyped games (Assasin's Creed, Call of Duty, Nintendogs, Brain Training)
2. Sports / Racing games (and in particular EA games and PES)
3. Long Frachise games (Mario, Zelda, FF, MGS, etc)
All other games will struggle to get some attention in Europe, thus America and in particular US comes to the rescue. Thus, by far US is the most important market in the world. If PS3 doesn't get some attention there (I'm quite sure it will after MGS and FF), Sony is in some trouble.
My themeforest portfolio:







