'30 Rock': The 15 Best Guest Stars, Ranked

We’ll always love Liz, Jack, Tracy, Jenna, and Kenneth, but an undeniable part of “30 Rock’s” appeal is the never-ending parade of guest stars that have marched through “TGS” over the past seven seasons. With the show signing off for good this week (blerg!), we’re celebrating by counting down the 15 best guest stars in “30 Rock” history. — Dave Nemetz, Yahoo! TV

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(15) David Schwimmer as Greenzo

The man formerly known as Ross Geller surprised us with his hilarious Season 2 turn as Greenzo, the eco-friendly mascot Jack hired to help NBC “go green.” (Or at least look that way while it continues depleting the planet’s resources.) Once Greenzo got a taste of the limelight, he turned into a militant environmental crusader who scolded the “TGS” staff for their wasteful ways: “Do you even bother to compost your ... more
(15) David Schwimmer as Greenzo

The man formerly known as Ross Geller surprised us with his hilarious Season 2 turn as Greenzo, the eco-friendly mascot Jack hired to help NBC “go green.” (Or at least look that way while it continues depleting the planet’s resources.) Once Greenzo got a taste of the limelight, he turned into a militant environmental crusader who scolded the “TGS” staff for their wasteful ways: “Do you even bother to compost your own feces?” Yeesh… even Phoebe Buffay wasn’t that nuts. less