Love love LOVE the Memorial Union. A visit to Madison would not be complete without stopping here for Babcock Ice Cream on the terrace's famous multi-colored chairs. There is nothing better than spending a summer evening on the terrace, listening to free, live music.
The music they bring in both for the terrace and at the Rathskeller is eclectic and always a good time.
People of all ages spend time here, it is not completely overrun by students, especially during the summer.
The historical architecture of the building is gorgeous, and although the lake isn't the cleanest lake, it still makes for a beautiful view, and there are multiple docks to go sit out on.
The bar in the Rathskeller is particularly ideal because they do not accept tips, which saves you quite a bit of money, PLUS they give you money for returning their plastic pitchers to them.