Kenshin vs. Shishio
Kenshin or Shishio, who's the biggest and baddest (Shishio)... I meen, who is the best? Kenshin won the fight, so he's better right? But their fight left many things unclear, for me atleast. First off, it was very unfair. Shishio had seen Kenshin fight before and had observed his technique (even though he only got to see one O.o), plus he had info on Kenshin's Amakakeru Ryu No Hirameki. Kenshin on the other hand had never seen Shishio fight, and knew nothing of his technique. Kenshin was also hurt from his previous fights with Aoshi and Sojiro, two very talanted swordsmen. And, to make things even worse for Kenshin, Shishio had the intention to kill him - Kenshin didn't, which probobly made him a little confused on what to do. With his Sakabato he couldn't do alot of damage either. As for Shishio, he could only fight for 15 minutes before overheating, and dying that way, plus he had to fight multiple opponents, though they were all severly wounded. After Shishio used his Guren Kaina (how was kenshin supposed to know his glove would explode? O.o) on Kenshin and he'd fainted, he was attacked by Saito, Sano and Aoshi, defeating all without receiving any damage himself (the only one who could've killed him was Saito, but due to his metal headband no damage was done. I wonder why Saito's Gatotsu dindn't pierce it though it could esialy destroy the big iron door into Shishio's private dojo?). During this time, Shishio had many occations to kill Kenshin while he was unconsious, but never did.

As Kenshin wakes up the fight starts again. Shishio tries to use his Guren Kaina again, but Kenshin (yay!) uses it on Shishio instead! He then attacks Shishio six times in a row, finishing with Ku Zu Ryu Sen. If Kenshin would have used a normal sword (or flipped his sword over), Shishio would be dead at this point. But, he isn't, he doesn't even seem to be espesially wounded! Now comes the fun part! They both decide to use their "special" techniques. However, the secret to the Amakakeru Ryu no Hirameki is that kenshin draws his sword with the left foot forward, and when Shishio (not knowing which Batto-technique he would use) notice it he blocks it! Then Shishio gets ready to use his secret technique (too bad we never got to see the complete one), Kagu Zuchi. Dragging the ragged edge of his sword against his sheath, the human oil on his blade starts burning, creating a giant vortex of fire, when suddenly, he's drawn towards Kenshin by another vortex of air, and he uses his technique again, stronger than before (all Batto-techniques have two attacks).

After this Shishio can barely stand, he's reached his limit; hes puking ^^,. Yumi, who's been there from the beginning, runs between Kenshin and Shishio (it's been alot more than 15 minutes now), begging Kenshin to stop, which he does, being too nice as usual.Shishio's sword pierces Yumi and stabbs Kenshin in his stomach. Kenshin falls down and stays on the ground. Shishio gets ready to deliver the final blow, drooling, his blood boiling. Nothing is stronger than the will to live! Kenshin stands up, but due to his wound he's unable to defend himself, and just a Shishio is about to kill him, he's engulfed in flames.

"A fight, unlike a duel isn't won by the guy with the better swordsmanship! - Sanosuke Sagara"
In a duel Kensin would've won, in a fight Shishio. My vote's for Kenshin, but who really is the best will remain unknown, until someone with power (like Watsuki-sensei) announces it (Kenshin *hint hint*)!

PS. I know this was a little short, but I didn't want to go through the entire battle. Hope this helps you decide who's the greatest ^^