@HK-42: You aren't a Revan fanboy are you? :P
On-topic: Though Revan is pretty strong, being the head of the Revanchist, going head-to-head with Mandalore and Malak (ok, Malak isn't a good example). He also killed a bunch of those stupid Selkath and Rakata :P I digress, I wouldn't rate him higher than Anakin/Yoda/Luke, at all. Maybe Mace Windu level of skill/power/strength/etc.
A tale of souls and swords, eternally retold.