I'm not using any on my own pala, but if I was I'd use one of the classic paladin/Arthas quotes from wc3.
(copied from wowwiki)
"Justice has come! "
"Foul knave! "
"You are past redemption!" <--- that's my personal favorite
"Light, guide my path. "
"Light, give me strength."
"I should be in command."
"I know what I'm doing. "
"There's no need to bow."
"For my father the king."