Created this thread as a go to page for working ExternalViewer strings for the different PDF viewers out there. In my case I was trying to get Sumatra to open a pdf in Bluebeam Revu,
Due to the lack of posts that dealt with Bluebeam specifically, it took a lot of trial and error for me to find a string that would work.
Feel free to post any working strings you guys are using, THANKS!