I know that visiting museums could sound a boring activity but for me is kind of amazing (I need to recognize that some museums didn't caught my attention) but finally, I like to take al look al least.
As I remember, there were museums that obviously need to be counted on the list like Van Gogh museum @ Amsterdam, Louvre (just after finishing Da Vinci Code haha), Madrid's Museo del Prado is also amazing. I also liked this exposition http://www.museoreinasofia.es/museoreinasofia/live/exposiciones/pasadas/dali-cultura.html
@ Museo Reina Sofia, it was about Salvador Dali and it has an amazing work for Dali by Andy Warhol. I mention Warhol because yesterday I started visiting Carnegie Museum of Art and remember my 2004' s walking around europeans museums, I found some Monet and Van Gogh paintings, (favorite artists in painting) and I was really excited about that.
Today I visited Andy Warhol museum here @ Pittsburgh (need to mention that I moved here and will stay for a long time doing a Master Program at Carnegie Mellon University). I like although I expected more of it. Looking Pittsburgh from the bridges is amazing also!