In a bar fight? Marino.
Won more big games? Marino.
Appearing to have a seizure at the line of scrimmage? Manning.
Crapping his pants at the sight of the Patriots? Manning.
In all seriousness, though, Manning is looking more and more to have a career that mirrors Dan's; lot's of gaudy numbers and success in the regular season, no Super Bowl win. I believe that no QB, as great as he might be, can carry a team to a Super Bowl win on his own. (Dan came the closest in the 1984 season, IMO.) Another example is Barry Sanders. He was the best RB I've ever seen, and how far was he able to carry those Lions teams?
Fair or otherwise, people will judge Marino and Manning according to the failure of their teams to win a Super Bowl. I don't think it's a fair judgement. Were Trent Dilfer and Doug Williams better QBs than Jim Kelly and Fran Tarkenton? It's a team sport, and our culture is too quick to hero-worship and to judge the superiority of the individual over the team. Success and failure in football is determined by the team. An individual might be able to have dominance in a game, but to cary a team to success through an entire year? I haven't seen it.
The importance of the team is one of the great beauties of football. It's also the source of some of it's slow tragedies, as we Dolphins fans experienced watching Marino's career.
Man! I can't wait for the season to get going!