With that being said, I think the best ever...the guy that they said, "the fate of the multiverse depends on you winning this one Super Bowl, who ya got?", I'm going with Joe Cool.  Montanna suceeeded EVERY opportunity he had, in any way the opposition tried to draw up.  Give me 10 free throws and if I make 6 out of 10, yeah, I'm good I guess.  But give me 10 and if I make all ten, that's just a bit more IMO.
		
		
	 
I don't know why people contain the conversation to Super Bowls.  The suggestion here is that it's better to lose in the first or second round than get your team to the Super Bowl and lose.  Montana lost in the playoffs 7 times.  So, no, he's not 4 for 4.  He's 4 for 11.
		
 
		
	 
Because the other side of that coin is he went to SO many playoff games and had a lot of success.  You have to be really good for a long time to even have the chance to play in and lose 7 playoff games.
But it doesn't have to be the Super Bowl as the caliber.  If you grew up in that era or you watched a lot of football during his career you may not have all the numbers in your head (the pro bowls, SB championships, MVPs, highest passer rating 5 years, etc, etc,)
 but you remember he just NEVER seemed to fail.  The Niners won and they won a lot.  They were always winning their division, always had gaudy records, were on prime time TV all the time which was more rare then.  Montana was part of one of the most notable plays (the catch) of the last 40 years.  You just watched him get it done over and over and when the NIners lost, you can probably count on one hand the number of times where you can say "Montana failed to do this or that".  He had something like 35 4th quarter comebacks.
In short, it just happens that when you think of him or what people recall of him is almost always him getting it done. ANd that's what being one of the greats is about.
And he did it in an era of great peers. THe QBS of the early 80's is probably the best collective group of a decade and he stood out among them all.
And he did it in an era of ferocious defenders.  Today we talk about JJ Watt as being unparalleled and there's not a lot to compare him to.  But in Montana's day, when teams still could hit and play., you had Lawrence Taylor, Mike Singletary, Bruce Smith, Reggie White, Charles Haley, Darrell Green, Deion Sanders.  Just a list that goes on and on and on of AWESOME defenders you had to play against every week.