There seems to be a trend of PSP racing games being painfully easy though, here it's not as bad as in Motorstorm but it's still a bit yawnsome through lack of challenge occassionally.
Try Gran Turismo. Bloody things hard as a frozen faucet.
I've started playing Dynasty Warriors Strikeforce again. The games so fun, why did I ever stop? According to my last save from a few months ago, I only played it about four hours last time. Very good action RPG, and very good action game just in general too.
Just because something is fictional, doesn't mean its not real.