Not that the quote itself is very awesome, but I thought the last scene in Episode 55 in the Kenshin/Soujirou fight is my favorite line. I might add it is only awesome in Japanese as well as the Soujirou VA in the dub is horrible:
""Ano toki anata wa...boku o mamodekuruna katanjanaidesukara. Anata ga tadashitoyunara. Nande Mamodekurunankotodesu?!?!"
"That night....you didn't protect me at all. If you really speak the truth, why didn't you protect me?!?!"
I think (IMHO) this was the climax of the show. The music, the voice inflections, the sword strikes...everything was perfect.
For those of you who read it anyway, this is a scene where Soujirou breaks. He blames Kenshin's faulty (cough pussy cough) philosophies for not protecting him (not necessarily Kenshin) and that only Shishio's philosophy saved him. The cliffhanger to this is amazing too (nothing like Saitoh stabbing Kenshin). Soujirou is charging Kenshin and it zooms in on Kenshin screaming "SOUJIROU!!!!" as Soujirou gets close to striking him.
AHHH! I wish I was at home so I could watch this again
