That’s the episode with the French art treasures. LeBeau is the one who gets into the truck.
Other good episodes include the one with Bob Hastings (of McHale’s Navy fame) as a downed Russian pilot and those with Italian Major Bonacelli (played by Hans Conried and Vito Scotti). I also liked the one where the POWs made (and had to destroy ASAP) recordings for German propaganda.
Fawlty Towers, Episode 6, The Germans
This one episode includes Sybil in the hospital with a toe problem, Basil in the hospital with a concussion, a fire drill and a fire at the hotel, the moose head, and the German guests.
Great lines:
One of my all-time favorites of any episode of any show is the Barney Miller ‘Hash’ episode, S3E11. I still watch it occasionally on YouTube, and I laugh every time I watch it. Jack Soo is at his best in that episode, as is Ron Glass.
Murphy Brown - “Send in the Clowns” where Murphy testified before a Senate Committee. The episode was a perfect parody of the Anita Hill/Clarence Thomas hearings, highlighted by the character Eldin Bernicki saying he was so outraged watching it that he too a bag of manure and put it in front of the TVs at the Sears store and so that now “He was no longer welcome where America shops.”
Northern Exposure - “Democracy in America” where the town has a mayoral election.
Did you mean “Heaven Sent”? I found “Hell Bent” to be a sloppy mess (as indeed was the other half of “The Zygon Inversion”, “The Zygon Invasion”) but "Heaven Sent " to be some startlingly original television.
Criminal Minds “Riding the Lightning.” The guy who played the sociopathical killer was excellent.
Coach - The Homewreckers episode
Hayden (Craig T Fox) seeks Luther’s (Jerry Van Dyke) companionship while Christine (Shelly Fabares) works on the weekend. While she is away, he nearly destroys her apartment.
As close to a perfectly written episode of television as I have ever seen.
Klink vs the Gonkulator. Classic how everyone tries to pretend they know what the titular device is.
Honorable mention: The General Swap. A nod to Mission Impossible, where the heroes “fly” a German field marshal to England down in the tunnels.
I also like the one where Hogan is an expert on the famous Norden Roll out the barrel!. The scene where the POWs read from a script while Klink listens in on his bug is hilarious!
“The Schultz Brigade” is good too. 
Futurama: The Problem with Popplers. Pure gold from beginning to end, including the fact that the title is a sendup of that of a well-known Star Trek episode.
Simpsons: A Streetcar Named Marge
South Park: Casa Bonita
MASH: Fade Out, Fade In. The first Charles episode, with the very end being one of the best MASH moments ever.
Big Bang Theory: The Dumpling Paradox. Maybe it’s just because I know someone similar, but Sheldon’s inability to ignore the extra dumpling just sells the character for me.
Night Court: One of the “Day in the Life” episodes, though I’m torn between the second (“Another Day in the Life”) and the third (“Yet Another Day in the Life”) for greatest.
So is “Der Krieg ist zu Ende”:
KLINK: So, Schultz. You work for the Schatzi Toy Company, eh?
SCHULTZ: No. I *own *the Schatzi Toy Company.
KLINK: Would you care for a cigar?
So is the one where Hogan convinces Klink there’s oil under Stalag 13:
KLINK: At last! Not only will I have a 500-year-old aristocratic name, but some money to go with it!
I could go on and on. 
New guy here. Surprised to see only one mention of Community- their experimental episodes and parodies/homages didn’t always work, but when they did they were as good as anything on TV.
In addition to Remedial Chaos Theory (mentioned before) I’d add Modern Warfare and my personal favorite, Critical Film Studies, which head-fakes as a Pulp Fiction homage before going in a completely different direction in every possible sense.
And while there’s nothing interesting about saying so, I think Breaking Bad’s Ozymandias makes all these lists for good reason.
I only didn’t mention a Community episode because so many of those episodes are so good that none particularly stood out as head and shoulders above the rest. Now that you mention Modern Warfare (the first paintball episode, yes?), though, I agree that’s an excellent choice.
Hogan shows his men a quick and easy way to reassemble the engine - with a hammer.
LeBeau - I think you forced it.
Hogan - It's a German plane. All it understands is force.
from Psychic Kommandant
There was an episode of (Denis Leary’s) *The Job *where a perp steals one of the detective’s guns and is able to hold Denis as a hostage in the basement bathroom. The gunman doesn’t speak English and DL doesn’t speak Spanish. However, the funniest part(s) is when his wife and then his mistress call him on the phone with THEIR problems, uncaring that Denis is being held at gunpoint. Hill-air-ious!
It’s not just funny, I found the whole ep well produced; including script, direction, etc.
Great for the wrong reason:
“The Great Vegetable Rebellion,” from (3rd season), “Lost in Space.” The absolute pits; at least once in the episode, Don West (Mark Goddard) is trying so hard not to laugh/look disgusted that he turns away from the camera while John Robinson is talking to Tybo, the CarrotMan–ya gotta love Stanley (“Cyrano Jones”) Adams, he’s a total professional. Some day, I want to get really wasted and watch that epi and see if I survive the hilarity.
“Moisture! I need moisture!”
One Barney Miller episode that hasn’t been mentioned is Guns. I suspect that scene wasn’t in the script, but was a brilliant idea from Max Gail. If you look real closely at Hal Linden you see he notices the camera is still running and stays in character.
This is the problem. Introduction to Statistics, Modern Warfare, Contemporary American Poultry, etc.
How do you choose???
There are a lot of choices for me- The Body from BtVS, Ronny/Lilly from Barry, Love’s Labor Lost from ER… but my all-time favorite would have to be Michael’s Gambit, the season one finale of The Good Place.
Holy crap was that a sucker punch. Telegraphed the entire season, yet still took me by surprise.
So of course I just spoilered it for myself.
That’s how I felt about the last episode of Blackadder, BTW. You knew it was coming from previous seasons, but not like that. (Atkinson’s discourse on how the war started is also a high point. If I ever teach WWI again, I’ll probably show it.)