The fight scene that got to me the most isn't really a fight scene between two people. It's when Luffy finally got to Ace and they were side by side and I thought hey, I get to see them kick ass together, nice!

...yeah. Marineford wrecks me every time. I also really like the brief Luffy vs Garp just before this, which packs a lot of emotional and moral complexity into a very short interaction, and it would probably make it a lot higher on my personal list of favorites if it wasn't completely overshadowed by what comes next. because Aaaaace.