I agree completely. Pirating games makes game developers less likely to spend lots of money making new games, and therefore ultimately hurts the pirates in the long run when there are no decent games being released anymore.
Yes, I have occasionally downloaded games, but only for the purposes of evaluating offline whether I like them or not. If I decide I like the game I buy it, otherwise I just delete it from my system. Usually games have demo's anyway so you can just get those, but sometimes the developers seem to forget to make a demo and you have to resort to the above to test it.