My ratings probably skew high for a number of reasons:
* I tend to not rate games unless I've played them at least twice. Of course, if I have a really bad experience with a game, I rarely engage in that second play!
* As the most addicted game-buyer in my groups, most of the games I play are my own, which are very rarely bought without copious prior research. So the odds are that I'm going to like the games I play. Also, since I own them, there's probably an upward bias (hey, I can admit it!)
* I like games. I'm normally willing to play most games, and since "willingness to play" is ostensibly the question that the ratings system asks of me, my answers skew towards the affirmative.