I don't own them all, but each time I run a scenario, or series of scenarios, I always think to myself, this is my favorite. I just did a 7 part series, "The Saga Local", a really great series of scenarios in the workshop, this series runs all parts of the route and has you doing pick ups and drop offs along the way. This really reminded me how much I enjoy this route, it has mountain grades, high speed plains running, double and single track sections, a lot of switching all along the route, and great scenery. What else could you want in a route! If this route was ever redone in TSW I sure wouldn't complain.
The route has got nostalgia value for me as it was one of the original routes in MSTS. Somehow Kuju/Microsoft managed to license the BNSF branding outside the US too.