有趣 (yǒu qù) means 'interesting, fascinating', used for things that engage your mind, like books, movies, or conversations. It is more intellectual and formal than 好玩儿 (hǎo wánr, 'fun for activities'), and overlaps with 有意思 (yǒu yìsi, more colloquial, also 'meaningful'). Use 有趣 when the interest comes from thought or amusement rather than pure fun.