I'll go to science museums for the history of science or to gawk at dinosaur bones or geological samples. If I actually want to learn some science, most museums don't have the same amount of depth as a college textbook.
Art and history museums. The weirdest display I ever saw was the Body worlds exhibit where they have cadavers skinned and showed all of the muscles, some with just the veins, in different positions. It's kind of hard to describe so here's a link.