Did the Millau bridge a few years back. The bridge itself is a great feat of engineering, the drive there and back is good, but crossing the bridge itself is a bit of an anticlimax due to it being a motorway and all the side protection measures obscure the view.
Another one I want to do is the Oresund road and rail crossing between Copenhagen and Malmo. A two and a half mile tunnel to avoid interfering with air traffic from Copenhagen out to a man-made island and then a five mile bridge into Malmo.
http://twistedsifter.com/2015/09/oresund-bridge-turns-into-tunnel-and-connects-denmark-and-sweden/