Watch Emma Stone play Roseanna Roseannadanna on SNL 40.

Last night's 'SNL 40' was probably the best anniversary celebration yet! There were so many great previous cast members who returned to perform their most memorable characters.

During the 'Weekend Update' skit, Tina Fey, Amy Poehler, and Jane Curtain (who are host alums) introduced many classic 'WU' characters, such as Melissa McCarthy playing Chris Farley's Matt Foley characters and Edward Norton playing Bill Hader's Stefon character. Emma Stone made an appearance during the skit and recreated the famous character Roseanna Roseannadanna (who was originally played by Gilda Radner). She did a really great job mimic!

Watch the skit below...