Unfortunately, a lot of the great views from the upper deck are now blocked by buildings that lack any redeeming architectural value. I used to love going to the top of the ramps on the 1st base side and looking across the Anacostia, down to the confluence* and out towards DCA. That, and being able to see the Capitol from a bunch of spots. No go no more.
* not The Confluence. There is only one The Confluence, which is in W. Pa.