a (good) catch

From King Dictionary of Contemporary Englisha (good) catcha (good) catchMARRYWANTsomeone who is a good person to have a relationship with or to marry because they are rich, attractive etc – often used humorously catch
Examples from the Corpus
a (good) catchHe went to it at once, looking for a catch, a way of releasing it, but there was nothing.The law has a catch, however.Since a doctor or a lawyer is a good catch, he can attract a woman whose family is wealthy.There is a catch, however!Within minutes, Honaker felt the telltale movement of a catch moving up the tube.A man in a uniform was a good catch in these parts.And keep medicines up high, also with a catch on the cupboard.He caught 89 passes last year, but he averaged just 7. 7 yards a catch.