Heads up! Both Steam and GreenManGaming have Civilization 5 and DLC on sale! It's also a free to play weekend for Civ. 5 on Steam!! So if you've never played the series I highly recommend checking it out.
http://store.steampowered.com/app/8930/?snr=1_quothttp_4__40
http://store.steampowered.com/app/8930/?snr=1_quothttp_4__40