Jennifer Aniston by George Pimentel/ WireImage.com Jennifer Aniston by George Pimentel/ WireImage.com

Playing Alec Baldwin's stalker is "really, really fun" for Jennifer Aniston.

The former Friends star shot her guest spot on 30 Rock last week and couldn't have had a better time, Us Weekly reports.

"It was awesome, really, really fun," Aniston said, describing the 30 gang as "stellar."

In the upcoming episode, Aniston, 39, plays Claire Harper, an old roommate of Liz Lemon ( Tina Fey) who clings onto Baldwin's Jack Donaghy during her visit to New York.

Season 3 of 30 Rock premieres Oct. 30.