I'm not sure how people do not manage to resist tbh. THe last game I bought was Just Cause 2 back in January for less than 1 quid. Before that, I had bought the Humble EA bundle. That was in August 2013.
Just this sale, I was tempted by Borderlands 2, Insurgency (it hasn't gone on sale yet, but I'm still not 100% sure I want it), Tomb Raider, Metal Gear Rising, Sleeping Dogs, Skyrim, Don't Starve, Payday 2, Prison Architect, Democracy, Far Cry 3 and Game Dev Tycoon. Each time I get tempted, I tell myself that even if I buy it, I will just play CS GO and Football Manager, and it is a waste of money.
I even have racked over €20 of steam credit selling CS GO items and trading cards.
You don't have to complete them. For the low, low prices it's worth it even if you play them for 1-2 hours then go back to CS:GO.
On that list, Borderlands 2, MG:R and Skyrim are the stand-out games. All excellent.