If Green Man Gaming gets its way, you're going to be playing through the Borderlands franchise for next couple of weeks. The online store currently has all three games discounted by 83 per cent, allowing you to grab the entire series for a little under $US20.
As GMG's "franchise of the month", Gearbox's role-playing shooters are all rather cheap -- $US5 for the first game and $US7 for the sequel and uh, Pre-Sequel.
Note that the Pre-Sequel doesn't include any of the DLC -- you'll have to spend another $US23.99 to grab the season pass. However, the other two games are the GOTY editions.
Still, if you do go the whole hog, $US43 remains a solid deal.