I visited this classic WHS for the first time recently, in November 2015. This was low-season, tourist-wise, but the city was doing a brisk trade in sightseeing nonetheless. We managed to get into the Accademia with only a 15 minute wait, and the Uffizi we were able to walk straight into! I can recommend the Palazzo Medici Riccardi for its Magi Chapel and Giordano ceiling. For a cityscape there is an excellent viewpoint to the southeast of the city walls, atop a hill. Also worth seeing is the Basilica of Santa Maria Novella, where there hangs an early Crucifix by Giotto (although unfortunately Masaccio's Holy Trinity - one of the first works to demonstrate a knowledge of the laws of perspective - is currently out for restoration). On the agenda for next time are Brunelleschi’s Pazzi Chapel (the ‘first’ Renaissance building) the Bargello museum and the Palatine Gallery, as well as the half of the Pitti Palace that we didn't manage to fit in.