Never saw anyone play before the late 80s, but here's who I'd put, in particular order, ahead of Brees (stats do the heavy lifting for QBs before my time):
Brady
Montana
Marino
Starr
Unitas
Staubach (this dude is criminally underrated)
Elway
Manning
Mahomes
When it comes to Tarkenton, Young, Rodgers and Favre, I think they're right there with Brees somewhere. Total tossup.
I've got Brees ahead of Moon, Warner, Kelly and those types. Don't think I forgot anyone?