There's a limited time coupon floating around "OCTOFUN1" that gives you 25% off of any digital download game. Apply it on checkout for the discount, then grab the Steam key after purchase.
I applied it to Sleeping Dogs (which is on sale for 29.99) and picked it up for 22 and some change. I would have waited until the December Steam Sale but it seems like a fun game to warrant the purchase now.
[Edit] I believe it can only be used once per account. But I haven't tried to get anything else with it.