The first sale is named “Luck of the Irish“, and lets you pick 5 games from their list to get at 90% off. There are a lot of popular indie games like Hotline Miami, Fez and Spelunky in the list, so this will be your best chance to nab them at a very low price.
You can also fill any of the 5 picks with a pot of gold, which for $2 selects a random game from their “pot of gold” for you. The catch is you don’t find out what you have gotten until you have bought. I ended up with Duke Nukem 3D: Atomic Edition as my random game.
The site also has a separate weekend promo happening, where they have discounted even more big games. Banner Saga is only $16.74, while there are also a few horror games like Outlast and Amnesia: Machine for Pigs if you are interested.