Nupe Kill Droma
Mr. Back-hand Slap
Why this has become a dumb post (and it's not just because I'm giving my 2 cents! lol):
You all are looking at only a couple factors on which to base your premises: Force power, dueling prowess, and... well, that's about it.
The dumbest argument you can make is: "so-and-so lifted a mountain, moon, airplane, or whatever and is therefore more powerful because another so-and-so didn't do the same feat."
The second dumbest argument is: "Person X > Person Y. Person Y > Person Z. Therefore Person X > Person Z." People are not mathematical equations, I'm afraid. If this is the basis for your opinion, then fine. But don't try to mask your opinion with "math-supported equations" so as to pass off your opinion as if it's "beyond-a-shadow-of-doubt" fact.
An important factor you are leaving out is "circumstance." What is the scenario of the fight? Are they fighting in the dark? In outerspace? Under water? Are they tired from a previous fight? Did one just witness someone close to him getting killed? I say this because the environment and circumstances matter. Would Vader have been able to save Luke if there were no shaft to toss Palpatine down? Maybe... maybe not...
The arguments you all are making are the same ones that sports writers make every week: "Team X beat Team Y, who also beat Team Z. Therefore, Team X has to be better than Team Z." Then teams X and Z play, and Team Z beats the crap out of Team X because they were playing in Team Z's home and Team X was missing two of their star players.
I know this isn't a sports forum, but let's use some logic and (better yet) common sense. Palpatine = Baddest Sith Lord ever. Palpatine > Vader. Therefore Vader shouldn't be able to destroy Palpatine. Going by the movies only (I'm excluding EU), Vader does, in fact, destroy Sidious even though he's killed in the process himself.
My point is that anyone can win "on any given Sunday." It just depends on the circumstances. So... let's bring back the original question: Who wins between Yoda and Darth Bane? It depends. Can you specify the cirumstances of the fight?