I love this discussion and the various points that have been made. For me, the question boils down to how we define "best quarterback."
If this is about which had the most pure talent: my answer is Thorson. (I think he could have accomplished a lot more if not held back by McCall's play calling and Cushing's O-line.)
If it is about production: hard to argue with Basanez in terms of stats. That 2005 season was simply a beast.
If it is about accomplishments: Schnur. Back-to-back Big Ten titles. 'Nuff said.
But if you ask me to pick which QB I would want on any team, which one I felt elevated his team the most, which QB I think could have been successful if you slotted him in instead of any other QB on the list: it has to be Persa. His efficiency in an offense where he really had no other help, where he carried the offense on his back was simply legendary. IMHO, he did more with less than any other QB that has been mentioned - Thorson had JJTBC, Basanez had Sutton, Schnur had D. Autry (and everyone else on those stacked 95-96 teams). Put Persa on those teams, and I have to believe he performs as good, if not better than he did in his years. Put those three with Persa's supporting cast? I'm much less certain.
And less anyone think this was just 2010: 2010 and 2011 are ranked #6 and #7 on the all time season completion percentage record list. He is the only QB with two seasons in the top 10. (
https://www.sports-reference.com/cfb/leaders/pass-cmp-pct-player-season.html)
The only reason he doesn't own the career record is because sports reference set a minimum of 875 pass attempts. Otherwise, his 72.7% would blow Colt Brennan's mark of 70.4% out of the water.
My other reason for picking Persa: of all the QBs on this list, I enjoyed watching him the most. He was a magician, both in terms of accuracy, but also in escaping the pocket and getting the yards needed to move the chains. In fact, before I even looked at the options on the poll, my gut reaction to the question was: "It has to be Persa."
Sidenote: I almost picked Schnur. I was in school those years, so I have a fondness for the 95-96 teams. But he wasn't even my favorite player on those teams - Autry, Bates, and Musso were, along with just about every player on the defense. In contrast, I had a hard time remembering any other players on the 2010-2011 teams until I looked the roster up.