HBO Max launched last May with the promise of a “Friends” reunion. It was forever bumped by the pandemic. But if it ever does occur, it could do worse than take its cues from “The Fresh Prince of Bel-Air Reunion” (HBO Max, streaming) which not only brings back the old cast, but honors those who have passed away (James Avery in 2013) and clears the air with the first Vivian Banks, Janet Hubert, who abruptly left the show in the third season. 

It all succeeds because it revolves around Will Smith, who is all in as he greets the former cast, including Jazzy Jeff, on a painstakingly recreated set of the six-season sitcom. 

There’s a promising new comedy premiering on the service as well. “I Hate Suzie” (HBO Max, streaming), which stars and was co-created by Billie Piper, is a vivid dark comedy on the underbelly of show biz. 

After 15 seasons, “Supernatural” (CW, 9 p.m.) comes to an end with its final episode, with Jared Padalecki and Jensen Ackles in their final battle with evil. To mark the occasion, it’s preceded by a one-hour retrospective “Supernatural: The Long Road Home” (CW, 8 p.m.). 

Vanessa Hudgens reprises her royal role in a second Chrismas sequel “The Princess Switch: Switched Again” (Netflix, streaming). 

The animated franchise comes a series with the new “Trolls: TrollsTopia” (Hulu, Peacock, streaming).

A second season comes for the animated “Cleopatra in Space” (Peacock, streaming).

“A Million Little Things” (ABC, 10 p.m.) begins its third season with a new set of problems. Still to be determined: whether Eddie survives being hit by a car at the end of season two.