'The Big Bang Theory' finale leaves a legacy of famous guest stars
The Big Bang Theory wraps its 12-season run with Thursday nights one-hour finale (8-9 p.m. on CBS). TVs top-rated ensemble comedy about a band of brilliant misfits has kept viewers laughing since 2007 with stars Jim Parsons (Sheldon), Johnny Galecki (Leonard), Kaley Cuoco (Penny), Simon Helberg (Howard), Kunal Nayyar (Rajesh), Mayim Bialik (Amy) and Melissa