What makes Favre so great?

I don't even think he is in the same cl as Montana, Marino, Elway. What makes him so great. He throws a crap load of picks and don't feed me the he takes chances cause I guess he took a little too many chances this year and screwed the Jets. But I'm not basing my opinion on this year alone. Even last year Packer fans were so blind about how much they love Favre that they basically didn't even notice he ended their season with an INT. Sure he is durable and a media darling but I don't see anything that makes him special. I even believe Peyton Manning is better then him. He only has 1 Super Bowl so what is so great about this guy?