I don't go to Roppongi much, but when I do I try to find something new each time.
exhibition of photography by Andreas Gursky, whose photography is similar to the kinds of "artsy" pictures I sometimes take. I should note that I didn't know who he was and I hadn't seen his work before going to the exhibition but was lucky enough to receive some free tickets. The other exhibition was a collection of American pop art, including several Warhol originals. I really enjoy modern/contemporary art and pop art is no different.
What about Tokyo Midtown itself? Well, there's nothing special that I can show you. Midtown Tower is the tallest building in Tokyo, with a Ritz-Carlton hotel on the top floors and some restaurants and shops at the top and bottom. Galleria is your standard indoor mall, with a very luxurious feel and luxurious stores inside. And the Suntory Museum of Art has a few exhibitions every year.
The oddity fan in me wanted to keep it and do something with it - mount it for display, perhaps? But I'm no bug collector and I have enough junk as it is.
Tokyo Midtown is located just north of Roppongi Station - the Oedo Line gives easy access, while it takes about five minutes to get there from the Hibiya Line station at Roppongi Crossing. The National Art Center is about 10-15 minutes from the stations and Tokyo Midtown. The art museums are open from 10 AM to 6 PM, and the mall stores are usually open 11 AM to 9 PM, restaurants usually 11 AM to midnight. Of course, Roppongi is a major nightlife district, and Tokyo Midtown is just north of it, where you'll find tons of restaurants and clubs open all night.