I make a distinction b/t art I admire for raw talent but would never put in my home. Here's a few that I really enjoy:

Dali - persistence of memory is one of my fave 'thinking' paintings.
Fuseli - the nightmare b/c it freaks me out everytime I see it
Sketches by DaVinci (the Mono Lisa sucks IMO) - I've seen an exhibit of his early drawings & they are simply incredible!
Rubens - prometheus, again b/c it is so graphic. Here's a link:
http://www.abcgallery.com/R/rubens/rubens114.html

BTW, this is one of those paintings its actually better to view online, lol. I've seen the originial & its MUCH darker.

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A woman would never make a nuclear bomb. They would never make a weapon that kills, no, no. They'd make a weapon that makes you feel bad for a while.