The Pitti Palace
The Pitti Palace was the graducal and royal residence in Florence par excellence. Nowadays the palace holds many museums and collections; the Palatine Gallery and the Gallery of Modern Art, the Medici Treasury (or “Museo degli Argenti”), the Costume Gallery, the Porcelain Museum and the Boboli Gardens.
The Palatine Gallery competes with the Uffizi Gallery for the wide selection of paintings, mosly Renaissance and Baroque masterpieces. The collection holds many milestones of art history such as eleven works by Raphael, the large canvas by Rubens, a few Caravaggios and many Artemisia Genitleschi’s paintings.
The Gallery of Modern Art holds a fine collection of Italian paintings and sculpture, dating from the late 18th century to the 20th century. The main attraction of the gallery are the numerous works by the Macchiaoli, a group of Italian painters active in Tuscany in the second half of the 19th century. They anticipated the Impressionists in painting outdoors to catch natural colour and light (though their poetics were very different from those of the following French painters).
Considering the numerous choices (and also the two kinds of combined tickets that Pitti Palace offer) I recommend for first-time visitors one of these guided tours of mine:
Palatine Gallery + Modern Gallery (3h)
Museo degli Argenti or Costume Museum + Boboli Garden (2h)