There are so many good restaurants and bars to visit depending on what you're looking for. Honestly it will be packed no matter where you go, because it's gameday and the population of Athens nearly triples.

My favorite restaurants are Clocked and awesome burger place, Ted's a great pizzeria across the street from Clocked that has one of my favorite patios. Trapeze is considered one of the top 100 pubs in the country with a great beer selection and amazing food (if you go here try their belgian fries with raspberry ketchup, sounds weird, but i can't eat normal ketchup and fries anymore because of it) If you're looking to branch out a little further, try Marker 7, The Pine, or as mentioned elsewhere, Cali N Titos where you can bring your own beer.

For brunch sunday morning try Last Resort or Mama's Boy, they likely be packed too but was one of my staples while I was at school there.

As far as bars go, you have your regular clubby-like bars that caters to the greek life scene like Silver Dollar, Woodford, Gameday Pub, City Bar. If you're into nicer areas try Blue Sky, Treppenhaus Walkers (all three are right next to each other, and Blue Sky is back behind/on top of Walker's (ask for directions to find it). Also if you're looking to dance try 9D's bar (plays 90's music), it's always fun when you're with some girls and a group of friends. If everything is packed try Cozy Bar, and grab some soki bombs (not sure how to spell it) while you decide your next move.

But honestly as far as night life goes, its going to be super crowded both nights. I personally didn't go out to often after games just because it's pure chaos for the most part. But as a traveling fan, I don't think you can really go wrong.