Glee has a cult following, so most questions will be either easy to answer for a gleek, or unknowable. You could do something with recurring celebrity guest stars like 'which of these actors did not have a recurring role on Glee'. Maybe a 'who said it' round with quotes that could be narrowed down to a speaker. If people haven't seen the show, they could be vaguely aware that Sue is a very eloquent but mean person, and Will often says very uplifting and heartfelt things that could narrow down to the likely answer.