Visiting the 122,500-square-foot Norton is like shopping at an enormous department store: The most pressing question is where to stop off first. The permanent collection alone, which comes to more than 7,000 works of art, includes five sections — American, Chinese, contemporary, and European art, along with photography — any one of which could occupy you for an hour or two. Then there are the special exhibitions, which are like big "for a limited time only" sales. A recent lineup featured seven running simultaneously: two photography exhibits, two showcasing glass art, one drawn from the Chinese collection, another with two big-name painters (Clyfford Still and Joan Mitchell), and one held-over extravaganza documenting America's cocktail culture. It was a typical roster. This past year, the museum's 70th, saw a string of winners, from the four artists who made up the trippy "Altered States" to the massive oil paintings of Jenny Saville to the gimmicky but gratifying "A to Z: 26 Great Photographs From the Norton Collection." And if the aesthetic equivalent of power shopping wears you down, you can always stop off for lunch at the café or take in the gift shop. Cash or credit?