There are so many parts that make me tingle.
You guys have to rewatch some of the earlier episodes, you'll be surprised at how much stuff you kinda forgot.
But umm Luffy vs Arlong, final moments; Luffy vs Enel, final moments; Luffy telling Robin to live, oh the whole Enies Lobby arc was just epic. I enjoyed Zoro's fight too.
speaking of Zoro, when he absorbed all the damage Luffy took.. that shit was insaaaaane!