Hounddogs Three Degrees Pizza
Hipster/Dive Bar (meant as a compliment):
Dirty Frank's Hot Dog Palace
Columbus Fish Market
Any? Taco trucks are fun.
Barley's Ale House #1
Maybe I'm missing some categories or should give some honorable mentions? It's hard because I would also suggest Tip Top / Hal and Al's / Surly Girl for standardish cuisine and we have tons of ethnic restaurants that I could suggest as well. Plus all of Cameron Mitchell's restaurants are pretty good.
Cool stop-motion-food-fight-which-represents-war-since-WWII link of the day:
*The first Wendy's opened ever was in downtown Columbus. It no longer exists.