GOG offers downloads of Saints Row 2 for Windows for free. That's the lowest price we could find by $9 and a great price for this hilarious GTA-like game (which stars Eliza Dushku and Worf from Star Trek. Worf!). Deal ends April 22 at 6 am ET.
The bigger news here is that Saints Row 3, Gat out of Hell and Saints Row 4 are on GOG Connect for the next week. If you own those games on steam, connect gives you a GOG copy for free.