There have been plenty of sales offers over the past few weeks, as one site or another is always running a promotion. Humble Bundle has package of great Sega-published games right now, and GOG has announced a huge St. Patrick's Day sale.
The "Luck of the Irish" promotion offers huge discounts on over 40 games, allowing you to pick a pack of five games at low prices. Alternatively, you can also take a gamble and have the site randomly select five games for you that aren't on the day's sales list for just $2 total. Highlighted sales titles for the first day include Fez, Dust: An Elysian Tale, Spelunky, Reus, and more great gams.
The deal will be running for a week with new games becoming available for sale, so keep checking back. The randomized 'Pots of Gold' promotion sounds pretty fun at just $2, even if you get a game in which you weren't particularly interested.
GOG is also simultaneously running a Big Games Weekend Promo, a more straight-forward sale just for this weekend. Today there are discounts on games such as Banner Saga, Outlast and more, but keep checking over the weekend to see what they're offering.
It looks like the Luck of the Irish sale is the way to go if you're looking to pick up a few games. Your deal comes in a bundle of five that you get to choose, each game discounted a pretty significant amount. If you're more daring, the Pots of Gold option does sound like a good deal even if you don't know what you'll be getting--unless you hate fun or surprises.