My list will likely upset some of the older guys here who saw guys like Johnny U and Otto play, but since I didn't see any actual games from them then they won't make my list.
Top 5 QBs:
1: Joe Montana - There was, is, and maybe never will be a better big game QB than Joe. In the ultimate game he was the ultimate performer. A perfect 4-0 in the Superbowl with a perfect 11-0 TD to INT ratio in those four games. 2 times he brought his team from behind, in the final 3 minutes of the game, to score game winning TD passes which helped him earn 3 Superbowl MVP awards in those 4 appearances.
2: John Elway - The heart and soul of the Denver Broncos. The man willed his teams to victories, and Superbowl appearances, when he was pretty much the only big time player they had. One of the top two come from behind QBs of all time. You gotta love how he gave his all out there on the field.
3: Tom Brady - I know a lot of people hate him cause he's the pretty boy QB and he plays for the Patriots but this guy is just cool as can be. 3 times he's lead teams to Superbowl titles with very little in the way of offensive weapons that really scare anyone at the WR spots. A 2-Time Superbowl MVP and barely 30 years old. Brilliant QB.
4: Roger Staubach - Captain Comeback. Led the Cowboys to 4 Superbowl appearances, gaining 2 victories (And if not for that great friggen Steelers defense very well could have had 4) and always seemed to give Cowboys fans hope, and opposing teams sick stomachs, that the game was never over, till it was over.
5: Brett Favre/Troy Aikman - Now I'll admit this is a tough spot for me to choose, and I'm also more than willing to admit there are probably many other QBs who deserve to be here above either, or possibly both, of these guys but this is my list and this why they're here.
Troy Aikman - Lead the Cowboys to 3 Superbowl Championships in a four year span (The first team to ever accomplish that) and picked up a Superbowl MVP along the way for his brilliant performance in Superbowl 27 that is sometimes forgotten/overshadowed by the brilliant performance of the Cowboys defense that night. Maybe the most accurate passer I've ever had the priveledge of watching.
Brett Favre - The Ironman. Heart, guts, determination, a will to win. Most great QBs have those qualities but this man had them in spades. Sure he was a gambler, took risks, and made some bad plays but the guy made even more big time plays that were positive and until Romo came along, with a similiar style, there might not have been a more fun QB to watch play. A play was never dead, till it was dead, with Favre and I liked that. A Superbowl Champion and lead the Packers to back to back Superbowl appearances. On on offense that even at its best was full of good players but only one great player in Favre he helped bring Titletown back to the National Scene after years and years of being dormate and forgotten.
The NFL all time leader in passing yards, Touchdown passes, completions, attempts, and the longest consecutive starts streak of any QB in the history of the game (270+ counting playoffs), not to mention the ONLY 3 time NFL MVP and he won it 3 straight years.