The first floor at the central market is an excellent place to eat. First floor meaning 2nd in US terms. Go upstairs. I don't have my blog link in my signature anymore, but I wrote about it a bit here -
https://saverocity.com/arewethereyet...d-in-florence/
Mods, nuke the link if that's against the rules.
As far as the best stalls, I think I can say I've eaten at all or at least most of them. My favorite was the fish stall, had a great fritto misto. Actually, I had two because my wife didn't want to eat the things with heads and legs left on them. Her loss! Second place was the hamburger stall. No kidding. Best burger I've had in my life. My 3 year old would recommend the gnocchi at the pasta stall. Also a good lampredotto sandwich on one of the interior corner stands, not as good as Da Nerbone downstairs, but better hours upstairs.
Happy to help with any Florence dining questions, high or low end