One Piece anime is really awesome specially when it comes to the fights it really brings the action alive. Like the one of Shirohige kaisuku dan and all their alies against the Navy in order to rescue Ace that was an epic fight. Here are some scenes I like from One Piece.
Fire Fist Ace (Hiken no Ace) vs Black Beard (Kurohige)
Didnt expected Akoji show up soo soon in the New World
Zoro being badass
Within other stuff there are many moments I would like to put in here but this is to begin with.