I think pretty much think the fight between Kenshin and Shishio from Rurouni Kenshin was awesome. There was a lot of twist and turns. From the opponent having, gunpowder in his gloves to biting Kenshin. What a cliffhanger when Kenshin was left lying on the ground while the others tried to beat the villain. Everything seemed so bleak till Kenshin got back up and fought Shishio beyond his limit. Even then, he was wounded and stabbed kenshin through his love's body (echoes of kenshin doing the same with Tomoe). That fight was one of the most memorable due to what was at stake for both fighters.