PARKS AND RECREATION
NBC, 9:31 p.m. ET
Tonight’s Christmas episode is almost ridiculously overloaded with guest stars. Megan Mullally, the real-life wife of Nick Offerman (who stars as Ron), returns yet again as Tammy 2, another of Ron’s easily excitable ex-wives. So does Lucy Lawless as Diane, his current significant other. And, in a first-time role as the formerly unseen wife of office buffoon Jerry Gergich (Jim O’Heir), look who shows up for Christmas: Christie Brinkley. God bless us, everyone. (And thanks for the shout-out last week, folks! Gives me major street cred with my college students.)