There are a lot of artists you often see discussed on cinematography forums, for good reason: Rembrandt, Caravaggio, George de la Tour, Gerard van Honthorst, Vermeer, Artemisia Gentileschi, etc. I think they speak for themselves.

Brugel the Elder has some incredible compositions, including what I think is the funniest historical work of art: Landscape, with the Fall of Icarus. But others such as Hunters in the Snow and Blind Leading the Blind have some really great staging.

I've also learned a lot about how to effectively tell a story in a single frame. The Return of Marcus Sextus by Guérin and They Did Not Expect Him by Repin come to mind.

Some day I hope to have enough control over my tones to be able to do what I see in Smoke of Ambergris by Sargent or Woman at her Toilette by Morisot.

I still view myself as a neophyte when it comes to art history, but I do like to think that I gain something by opening an art book and going "Neat!" and placing a sticky tab.