I'll say it, by damn. I hate "Old Time Rock and Roll." It would be tempting to select la Gonza for worst, but I'm going with your collective list of 80's progenitors (Styx, Foreigner, Journey--not the Doobies though) because they dominated the 80's with what for me was the essence of popular but vapid music, keeping better musicians out of the spotlight. Looking through this Best 100, there was a heck of a lot of good, individualistic music. The era was fragmenting in many directions (some of which I've discovered relatively recently, like Ryuichi Sakamoto and Yellow Magic Orchestra--both of whom show up in the second 100). I thought of these excellent works as outside of time (e.g. Pavilion of Dreams or Music for Airports 1), but in retrospect, the late 70's / 80's were much more complex than dominance by the homogenized top bands of the time would indicate.

I don't know Van der Graf Generator (reviewers I admired back then seemed to like them). I believe they're having a bit of a renaissance now, as is prog in general.