Over its 15 years on the air, ER has had some pretty memorable guest stars — including a Gilmore Girls alum who's clocking in for the show's final episode tonight. In lieu of a traditional brainteaser today, I thought I'd test your knowledge of which famous — and soon-to-be famous — stars appeared on the NBC medical drama over the past several years. Good luck!
How Well Do You Remember the Guest Stars of ER?
Which former Gilmore Girls star will make her first ER appearance on tonight's finale?