SEASON PREMIERE: Between the ABC and CW prime-time incarnations of this amiable improv comedy series, this marks the Season 12 return of Whose Line, in which host Aisha Tyler challenges her cast members – Ryan Stiles, Wayne Brady, Colin Mochrie and others, along with the week’s celebrity guest – to have fun with characters and situations she throws at them on the spot. There aren’t many “fun for the whole family” shows left on television, but Whose Line Is It Anyway? is one of them.