I mentioned XCOM in the OP. I managed to complete that recently on Impossible!![]()
Civ 4 or Civ 5
Galactic Civ II is awesome worth reading this http://www.computerandvideogames.com/195920/blog/galactic-civilizations-diary-days-1-26/
Total War series is good, and Rome II is coming in Sept.
+1 I loved Blood bowl the board game as a kid & when I saw it on steam I could not resist, so glad I did! it really is a very good conversion of the of the board game.Completely different from other suggestions but I got Bloodbowl the other day and I'm loving it. Can be had from here for about a fiver http://groupees.com/bm8 along with a **** ton of indie games.