What song plays at One Piece when Luffy epically defeats Lucci and Crocodile?

Maybe you could search for it on youtube, something like Luffy vs Luccy & crocodile ost. You can also search for OST's, I don't really know which episode you're talking about but based on when the episode is you can try some OST's... I'm sorry I couldn't help you more but if I were you I would search on youtube :)