Firenze Card

The Firenze Card costs €85 and is valid for 72 hours (from the first time you use it) offering priority access into 72 museums, churches, gardens and villas and special exhibitions (including the Uffizi) without the need to make reservations, except for the Uffizi and Pitti Palace, which you'll need to reserve, Brunelleschi's Dome at the Duomo di Santa Maria del Fiore, where ticket holders should book in person.

If you have the most up to date smart phone you can extend it by two days as well (currently free, but could return to €28).

There's also a Firenze Card+ for an extra €7 that includes bus and tram travel (but not the Florence Airport shuttle bus) and Wifi in the city.

Children under 18 get in for free with the card holder.

Whether or not it's a good deal greatly depends on what you want to see. Do check closing days as well so you don't miss out.