These are the most memorable Glee guest stars! Sarah Jessica Parker, Kate Hudson, Ricky Martin, Neil Patrick Harris, Demi Lovato, Olivia Newton-John, John Stamos are some of our favourite guest stars on the hit musical show!

Carrie Underwood, Kristin Chenoweth, and Christina Applegate's medley of "Be My Baby", "Leader of the Pack", and "Will You Still Love Me Tomorrow" from the Carrie Underwood: All Star Holiday Special in 2009