Ok, Pac, stay strong... It's fortunate that BoI:Rebirth and Darkest Dungeons don't have deep discounts, because I am looking forward to playing them... sometime.
Invisible Inc. is cool. Definitely recommended. But to be fair I am a huge Klei fanboy since freakin' Mark of the Ninja. Note that it came out less than a month ago, so don't expect great discounts.
Paper's Please is... something. Not a game though. It's good, but if you buy it, you should know that beforehand.
Don't Starve is an interesting, very imaginative roguelike / survival game. Also by Klei.
By the way, this week's Humble Bundle is ridiculously good: World of Goo, Super Meat Boy, Dustforce, Limbo, Braid, Dungeon Defenders, Risk of Rain and Antichamber. You can get them all for 6 bucks. Just sayin'.
EDIT: Oh, and GOG is also having their summer sale right now. They don't sell exactly the same games as Steam, so you might want to check out what they have.