Lungarno23 Restaurant
Somewhat upscale for a burger joint, but still shorts acceptable. On the Arno with a great New Orleans-style patio. Main fare is burgers from the local cows (Chianina). They also have very good pasta dishes. Background music was mainly 70s and 80s American classics. Some local microbrews as well as European beers. Fries were American style. A good spot to get some American treats when you want a break from Italian.
Club Culinario Toscano da Osvoldo
Felt a lot more local...I was the only guest not speaking Italian. Main menu plus daily specials. Felt like high end, sophisticated menu in a casual setting. Small restaurant. Mainly 2 and 4 tops. Very small outdoor patio. Had fried minced meatballs, fried artichoke hearts, and bread. Highly recommend.
Trattoria La Casalinga
Very casual dinner spot next to Basilica di Santa Spirito where Michelangelo's wood sculpture of Jesus is housed. Very casual trattoria (shorts fine) with kind and quick service. Gluten free pasta and bread. Sorbet (coffee, lemon, etc). Had an excellent pappardelle with duck ragout. Tiramisu was nice. $2 cover charge per person. Would go again for great value, really good service, casual, quick service. Andrea was a manager who was very kind.
Gustapanino
On the square in front of Basilica Spirito di Santo where Michaelangelo's wooden crucifix sculpture is houses. Great patio seating. Traditional Italian pastas as well as hamburgers and sandwiches. I really enjoyed the Scarpaccia sandwich which is salami, black truffles, and honey on fresh focaccia bread. At 7 Euro, also very good value.
Enoteca Pontevecchio - Wine, EVOO, balsamic tasting
This is a small, non-descript wine shop. Really cool. Around back they have four 4 top tables. They have free tastings all the time they are open for wine, EVOO, etc. Will ship wherever. Only Italian. Fun way to kill and hour here, get some A/C, learn, and ship home (and bring for at the hotel/house here). Great feel.