I have a Visual Studio solution that's started taking longer and longer to load. In fact it was taking up to 5 minutes to load this solution which meant that I'd leave the solution open for days just so that I didn't have to reload it. Another symptomatic clue that all was not well in Denmark was that it was taking several minutes for the IDE to be usable after I stopped a debug session with Shift+F5.
My first stab at a solution was to create a new one in a different directory and add all my projects to it. Worked like a charm and the new solution loaded lightening faster (couple of seconds) and I could exit the debug session in about 3 seconds.
Although happy that I'd solved the problem I was then lucky enough to notice that in the original folder next to the solution's .sln file there was a Solution User Option .suo file which was a whopping 11Mb in size. I deleted this file and opened the original solution and discovered that my solution is now loading and exiting debug lickety-split again.
It might be my unorthodox way of exiting debug sessions with Shift+F5 that's causing this file to grow in size. I'll keep an eye on it's future growth and report back here if I learn anything new.