Didn't we have one of these before? Hmm, at any rate stand by my Civ over Mafia, unless you REALLY like old gangster films. Civ is such a lovely combo of great ideas.
Civ 5. It's got the world domination of Risk combined with the resource management of Catan. It's a pretty big time waster, though, so be warned.
Don't buy Civ 5. I don't know anything about Mafia 2, but Civ 5 is a huge, pointless waste of time. You can't even get Metal Gears until the last few hours of a game. It's awful.
Yeah, but I had to put up with my friends playing this unfun bullshit for hours at a time instead of going out and mugging preschoolers with me.
They're both great, but I've put 1238 hours into Civilization V and 14 into Mafia II, so I'll let you be the judge of which one I like better.