Serious, I don't know which is better for me, but I think I would play better in tournaments.
I don't play much cash games, because I don't like them. You'll playing with your whole real money stack most of the time and it's too dangerous for me. When you're playing a tournament, you may have a tournament with only $1 buy-in with a stack of $100. This is great to play, because you're playing more hours with your stack than playing on a cashgame.
That's my opinion, and ofcourse, I'm playing tournaments all the time.