I seem to find great deals on steam... I'm actually a fan of the whole thing. Steam takes care of patches and puts everything in one nice and neat place. Plus for MP games it's *very* nice being able to have a friendlist and see who's playing what and blah blah. Meh... I can't say I have much to complain about as far as Steam goes.
Actually I will say this: I have impulsively bought games on Steam that I would have otherwise
never bought had I needed to drag myself to the store or was forced to wait and have it shipped to me. Sometimes this has lead to regrets and a waste of money... but I blame being part of the "now" generation more than I blame Steam.