To celebrate the opening of the baseball season, GameStop is offering MLB 2K10 (digital download only, through their download service) for a mere $2.99, 90% (or $27) off the usual price. This deal is only good today, April 5th.
Also, a few relevant notes from ShackNews:
Each purchase includes three licenses, which, according to GameStop, "means you may install the game on other computers and activate it up to 3 times." Be forewarned that GameStop will automatically add a $3.95 "Download Insurance" charge to your cart alongside the game--meant to ensure that "a back up copy of these Digital Good(s) will be available to you for download for up to eighteen (18) months from the date of purchase"--though this can be removed. Oddly, it's not clear how long the download will be available if that insurance is not purchased.