What I like most about this anime is the ambition of its characters. They put everything when they fight or chase their dreams. The main character, Monkey D. Luffy, is a simpleton. He believes that the one who lives as he desires is the king of the world, and he does so. He dedicates his life for achieving the top, being the Pirate King. He has a huge ambition which is later introduced as "haki" and makes him even powerful in fight. The crew mates of Luffy, the swordsman Zoro and the kick-fighter Sanji are strong warriors as well. The put their lives on the line and make several death matches agains formidable enemies, each of them was great to watch.
This anime has both superhuman strength fighting scenes and swordsplay. There is a vast collection of characters, some are funny, and some are making it serious. You will become addicted to this anime as you travel through its fantastic storyline.