I like what Namco did with Tekken Dark Ressurection. Sure, it wasn't an original game in that it had already appeared in arcades but this was the first home version of it... one hell of a technical feat. Not only that, but that added a hell of a lot of features and Tekken is perfectly suited for the PSP.
Without a doubt the best PSP game I own... at least until my imported copy of MGS:PO arrives, then we'll have to see. Tekken and MGS are my two favourite game series of all time. It's great to know that their PSP games are just as good as the others.
Screw lazy developers like EA.