Luffy's fight with Crocodile where Luffy uses the comeback "If you're one of the seven warlords of the sea… then I'm the EIGHTH warlord!!!" and then there's dead silence between them.
Luffy trying to eat Crocodile was funny... as was Luffy trying to stamp on the sand to knock him out.
Bon Clay calling Crocodile "Zero-chan"
Crocodile saying "why should we be limited to defending? We're on a battleship after all" after they escape Impel Down, and Buggy taking credit for this idea.
BUGGY RIDING THE DOOR and Mr.1 saying "why did you come?!"
Buggy opening the gates of justice because he's the messiah.
Nami: thank you, God~!
Robin: I thought you were scared of God...?
Nami: pfft, God? What does that matter? I just want the treasure!
Robin:......b-but you just said "thank you god"
Zoro: don't bother with her. half the time I don't think even she knows what she's saying.
Zoro and Luffy fighting, Valentine and Mr.5 not being able to stop them but Nami taking them out easily with her fist o' tough love
Wanze.
Duval. Funniest thing ever. Especially Brook's reaction and:
Luffy: ..... well, then, Sanji we'll just let you take care of this-
Sanji: are you implying that this is MY fault?!
Nami: wow she's so sexy! If she were MY secretary I'd be happy! wait a minute- I'm not a man!!!