I still think he's the best QB I've ever seen play; but I'm relatively young and my legitimate NFL football watching days only date back to the 03 season.
Really, the only guys you could put against him are:
Tom Brady- I could field the argument. Brady is pretty cool in the pocket and makes great decisions, but when he gets harassed the dude looks ROUGH. Most statues like him tend to look like shit when they're constantly being pressured, but I take points away from him for not being a bit more mobile (like an Aarong Rodgers).
Brett Favre- No. **** that guy.
Eli Manning- This has come up a lot lately with his 2 Super Bowls, but I think the dude is just lucky like a mother****er. They got hot at the perfect times to make those runs, but they pretty much backed into the playoffs in those two Super Bowl seasons and you can point to two unbelievably lucky plays to get the victory (the helmet catch by Tyree and the Welker drop last year, although his deep, sideline pass to Manningham in the last Bowl was amazingly clutch).
Drew Brees- He just hasn't been as good as Peyton.
Aaron Rodgers- I think he's the most physically gifted and complete QB in the league, but he hasn't been doing it long enough for me to stack him up next to Peyton.
Donovan McNabb, no. Ben Roethlisberger, no..
"I don't know how to put this...but I'm kind of a big deal"