Stronghold Kingdoms immediately, Stronghold Crusaders HD after instructions that take under 10 minutes
Follow the 'Special Directions' on the deal page to obtain both Stronghold Kingdoms and Stronghold Crusader HD for free.
Fans of medieval strategy games should take a look at this. Stronghold Kingdoms sounds like it may've been infested by trolls and has its share of problems, but free is hard to argue against in terms of price - and more importantly, Stronghold Crusader HD sounds like it's actually a good game. (You can always delete the former after getting the latter free.)