CBS announced Wednesday that of its scripted Friday-night dramas, “Numb3rs” and “Miami Medical” are goners.

The network said it was a tough call whether to keep “Medium” or “Ghost Whisperer,” but ultimately decided on the former because its crime-solving element was more consistent with the rest of the Friday night schedule.

But as the fate of the supernatural series had been up in the air, both shows’ finales seem nicely set up to be either season or series enders.

On what will be the final “Ghost Whisperer” (7 p.m., CBS), a haunted hospital poses a mortal challenge to Melinda and her son. Over on the last episode of the sixth season of “Medium” (8 p.m., CBS), Allison’s brain tumor resurfaces, setting up the same kind of cliff-hanger that ended the fifth season.

On “Miami Medical” (9 p.m., CBS), a rampaging alligator fills the wards. By evening’s end, I don’t think only the alligator will be dead.

“Kitchen Nightmares” (8 p.m., Fox) wraps up its second season with cranky chef Gordon Ramsay revisiting some of the eateries he has advised to see if they’ve remained on track.

But fans of Ramsay won’t be without him for very long. His cooking-competition series “Hell’s Kitchen” returns for its seventh season June 1.

“Kitchen Nightmares” will return for a third season, but not until early 2011. In September, Fox’s always problematic Friday-night schedule will consist of “Human Target” and the just-launched “Good Guys.” The network must hope they last longer than their 2009 Friday-night fixtures “Brothers” and “Dollhouse.”

Nobody ever sets out to write a bad season-ender, but sometimes they happen. The “Dynasty” cliff-hanger that resulted in the entire cast being machine-gunned at a Moldavian wedding ceremony led most of its audience to believe that the over-the-top soap had gone off the rails. The “Who Shot JR?” episode of “Dallas” had most of the country wondering all summer. But later, when “Dallas” explained away an entire season as a dream, the show ticked off fans and the finale became a template for TV cop-outs. The “Seinfeld” series finale that sent the cast to prison left most viewers unsatisfied, and the enigmatic “Sopranos” send-off baffled and outraged many of the show’s ardent fans.

Today marks the 20th anniversary of one of the most creative, funny and fondly remembered series finales of all time. On May 21, 1990, Bob Newhart woke up in bed next to Suzanne Pleshette, ending the “Newhart” show with Bob telling his “Bob Newhart Show” co-star that the entire series had been one long, bad dream. A gimmick that had been derided on “Dallas” was transformed into brilliance and a well-deserved place in TV history.

Tonight’s other highlights

• Taylor risks much to put his team first on “Friday Night Lights” (7 p.m., NBC).

• Janel Moloney (“The West Wing”) stars in the 2005 TV movie “Amber Frey: Witness for the Prosecution” (7 p.m., Lifetime).

• Hidden cameras capture dilemmas on “Primetime: What Would You Do?” (8 p.m., ABC).

• Telford falls under suspicion on “Stargate Universe” (8 p.m., Syfy).

• A cranky veteran (Clint Eastwood) makes an uneasy peace with his neighbors in the 2008 drama “Gran Torino” (9 p.m., Showtime), directed by Eastwood.

• Steve Guttenberg (as himself) makes Roman an offer on “Party Down” (9 p.m., Starz).