Plants vs. Zombies is so worth it.
I pre-ordered it because their trailer was just too good and the game does not disappoint. It never really get hard, but it does get pretty intense when you have to hold that last line of defense and strangely, as cartoony and kiddish it looks, it really does create a sense of urgency to prevent the zombies from eating your brain.
My friend was over my place playing Fatal Frame II and saw me playing it and was like "hey, what's that, looks cool!".