For a complete noob? Endless Space. It doesn't have the depth of Gal Civ 2, but it does actually have a useable interface. But if you are going for the sales, Gal Civ 2 is always recommended as an amazing game.
Once you have the swing of the genre, Gal Civ 3 might be out and about so having an understanding now will not hurt.
Stick with Civ V until you feel comfortable. Neither of those games are particularly friendly to people who don't know what they're doing.
thanks for the replies, guys!