If it came down to a fight, Revan. Kreia's not a fighter. Even so, Revan's a great strategist. Kreia, on the other hand, is a manipulator.
Traya has something more than manipulation and the Darkside of the Force going for her, she has cunning and understanding... understanding of battle and the consequences of every action.
Even at the height of his power, Revan was blind and unable to see past his glory, his vision. This is demonstrated by the Mandalorian wars when he chases them into the unknown regions and discovers the Sith empire, falling under the Emperor's control.
His short-sightedness is demonstrated again when he returns to known space and broke free from the Emperor's mind control. It is hypothesized by Kreia that Revan did not intend to conquer the Republic but save it by unifying the galaxy and preparing for the Sith's assault, under his banner. His downfall here was his lack of understanding of the culture he was now basked in; the Sith-Betrayal, by his Apprentice Malak.
After Malak's betrayal comes the physical memory loss, where he was short-sighted because of his inability to remember the past. Imagine if he knew of the empire that would come, do you think he would want the Star Forge destroyed?
And the final example of Revan being blind: his defeat at the Foundry... justification of exterminating an entire culture, an entire SPECIES, and being ganked by 4 lesser heroes of the Sith Empire.
Darth Traya did not have this fault, this short-sightedness. She always had a plan, always thought days, weeks, months... years ahead, and the one time she did not understand, she did not see, with Meetra Surik trying to unify the Jedi, she figured it out and tried to adjust accordingly.
Strategy is more than good leadership, and a good General is more than natural charisma.
As far as a 1 on 1 fight... that has already been debated, I have yet to see any canon Revan powers that match Traya's abilities to sever the force, force drain, exploit shatterpoints, manipulate wounds, etc.