I haven't seen much of anything posted here about Athens. I've been to Athens a decent few amount of times. Here's where I eat:
Your Pie - This is a regional create-your-own-pizza chain. It's set up kind of like a Subway and you pick the ingredients you want on your pizza. 6 minutes later, it's done. There are three locations in Athens, one of which is the very first Your Pie. My personal favorite pizza that I've created: 1/2 BBQ Sauce + 1/2 Spicy Thai Sauce base, soy cheese, black olives, onion, minced garlic, corn, roasted red peppers.
The Grit - This is all vegetarian diner style fair. Pretty good amount of vegan options.
Clocked - Clocked has good veggie dogs and decent black bean burgers. 50s diner feel. Horror movie posters on the wall.
I know there are a bunch of other places; these three are just my go-tos. Anyone else?