Green’s Dictionary of Slang

(US campus) a person, event or object that is currently fashionable or stylish.

[1934		Charleston (WV) Daily Mail 31 July 6/8: A ‘hot ticket’ is a popular show on which the ticket speculators are thriving].
1963		F. Kohner Affairs of Gidget 62: He’s living in fat city [...] accosted by all the hot tickets in college town to hit the sack with them.
1970		(con. 1950s) H. Junker ‘The Fifties’ in Eisen Age of Rock 2 (1970) 103: After a date they would ask, especially if he had a rep as a hot ticket [...] Get much?
1980		Eble Campus Sl. Fall 3: hot ticket – cool, in the know (usually used sarcastically) ‘You think you’re a hot ticket with that new shirt on, don’t you?’.
1987		T. Wolfe Bonfire of the Vanities 404: You know, more of a . . . hot ticket.
1999		Observer Screen 30 May 1: Salma Hayek, this season’s hot ticket.
2000		Indep. 25 Mar. 19: The hottest ticket in Tinseltown.