Your parents might want to visit the museum while you want to hike in the forest, but your brother, the hedonist, just wants to lounge by the hotel pool and eat cake. A hedonist values sensual pleasure above all else.
Hedonist comes from the Greek word hedone "pleasure" and is related to hedys, which means "sweet." Although this noun did not make its first appearance until 1822, the word was created as a reference to an ancient Greek philosophical system known as the Cyrenaic school. The Cyrenaics taught that pleasure — particularly physical pleasure — is the greatest good. If you need some examples of modern day hedonists, think the many celebrities today who are only famous for going to parties.