This is one of the rare examples of an exhibition website that seem almost more art-worthy than its content… (I don’t mean to editorialize, just to point out that the design of the website is pretty amazing.)
Zero showcases the 2015 exhibition at the Guggenheim museum in New York on modern art from the 50s and 60s. The works are accessed via a clock-like menu, with instant views on mouse-overs. You can view themes or individual pieces, with zoom and more information available.
Whether you like that style of art or not, the web is worth taking a look at for the stunning design. Very clean, playful and luminous.