You may have noticed that Steam is having one of its crazy-ass sales, this time under the name of "Perils of Summer", pointing out the dangers of leaving the house during the Summer months. (I'm at the beach right now! Woo!) As you might have grown to expect there are some ludicrous daily offers, and you can go find those - we're not their advertisers you know. However, we do want you to play great games without paying lots, so it's worth pointing you in the direction of Didimatic, a site that lists all the current sale prices on the various digital download sites. (Didimatic is short for "the digital-distribution-o-matic 2000", of course.)
Which contains the mind-boggling list of sale prices on Steam that will be that way until the 4th July. (Why does Valve think the Summer ends on Independence Day? What do they know? Are they planning to blow up the Sun?)
If you check Didimatic it lists sales for Direct2Drive, GamersGate, GOG, Impulse and Steam, with the latter currently boasting a ridiculously long list. GamersGate's isn't exactly a short list, and well worth exploring. However, Steam's is still five times longer, making them the winners of a competition no one was having.
Don't say we never do anything for you.