Well of course I would put Zach first as he was having an MOP season before being injured and I think still has the lead in QB rating and TDs (although that might have changed in the past couple of weeks). Judging from many of the comments that I saw in comment sections on articles when he was injured, many others in the league found him entertaining and fun to watch too.
Hank has certainly thrived with a much improved supporting cast of receivers
Jennings gets my nod as the most amazing rookie QB to start consistently.
I like Mathews, but he needs more time to develop and his lack of mobility while still trying to read a defence has not helped him. I think he'll be a good QB given more time.
I'll go along with your choices there FYB. I'd also put Mitchell and Collaros up there for me if it were not limited to 3.
Jennings was a delightful and welcome surprise for the Lions. Burris? Man, what more can CFL fans say about this guy? He will be very difficult to beat if the Redblacks are in the GreyCup.
Reilly? He has always been one of my favorites.
By the way…as an aside…
I think some of the guys who answered may have been thrown off a tad with the way you phrased the subject title. Though you qualified the subject in the content, it is understandable when someone reads, "Top" 3 QBs, that it is natural to assume the writer is thinking "best" 3 QBs. Some people don't read word for word everything that is posted. Some read the subject line and start formulating their answer.
Bo Levi Mitchell
Burris, Mitchell and Harris are the only QB's who have pretty much played a full healthy season compared to many who have not or were added later like Jennings or Reilly who came off the injury list from the start of the year.