The entire Just Cause Bundle -82 % http://store.steampowered.com/bundle/2277/Just_Cause_Collection/
Doom -50 % http://store.steampowered.com/app/379720/DOOM/
Titan Quest, a great Diablo-like action RPG -80% http://store.steampowered.com/app/475150/Titan_Quest_Anniversary_Edition/
Do you like strategy games? Are you someone who understands that game graphics are not important? Do you also enjoy playing older games?
Then Stronghold HD and Stronghold Crusader HD should be perfect for you.