I second (third or whatever) West Wing, In Excelsis Deo.
Twin Peaks Where Laura’s killer is revealed.
All in the Family–The Christmas episode when Beverly LaSalle, Edith’s cross dressing friend, is murdered in a “gay bashing,” and Edith loses her faith. The second best is the where Edith thwarts a rapist by pushing a just out of the oven burning chocolate cake in his face.
When I read on the Internet that Gordon Jump had died, the first words out of my mouth were “As God is my witness, I thought turkeys could fly.” The person next to me cracked up.
In addition to most of what’s been listed,
Coupling (the British version) “9 1/2 Minutes”
9 1/2 minutes of action is filmed from three different perspectives, and what seems just silly all ties in together at the end. Either there wereone hell of a lot cameras on the set, or the cast duplicated the action in the background exactly multiple times.
Blackadder Goes Forth: Goodbyeeee
The very last episode of Blackadder. (But what about that one-off episode) Yup…the very last episode. One of the best examples that a comedy can do decent drama any time.
The Simpsons: The one where Moe has debts
[Homer]Must…kill…Moe…WEEEEEEEE…Must…kill…Moe…WEEEEEE[/Homer]
The Adventures of Pete and Pete: Nightcrawlers
The first ever episode I ever watched. Little Pete tries to stay up for 2 weeks or something similar. It was like the childhood you always wanted.
Dear God. Don’t you people know not to ask questions like this where I can see them? Now my productivity for the day is shot. Well, it’s not like I was going to be doing much anyway… sigh
My favorite episode of Buffy the Vampire Slayer is The Zeppo. Not just because Xander saves the day while the rest of the gang are upstairs saving the day. But because of the moment between Angel and Buffy, when they’re getting all apocalpytic and maudlin, and Xander stops by - thinking of telling them about the situation he’s in - stomping all over the moment. And as soon as he leaves? They’re back at it. As if nothing happened.
Many of my favorite individual episodes would come from The Simpsons(Marge vs. the Monorail), South Park(the one with Christopher Reeve, I think), Mystery Science Theater (Deathstalker), Buffy, Angel (Smile Time!) and the like.
But there are just too many to choose from! Don’t make me choose!
I can’t believe it took this long to get to this one.
I concur. The last 10 minutes of that episode still gives me goosebumps, and I bet I’ve seen it at least 15 times.
Exactly. And there’s an episode further down the line where Picard dallies with romance, and at the end, he’s playing his flute in the Jeffries tube… :Sigh: 
The emotions that that sight summons in me is just further testimony to how damn good “Light” was in the first place.
Oooooh, thanks for reminding me…
Twin Peaks Pilot episode. … brilliant
Another vote for The West Wing, Two Cathedrals – the whole storyline ties up nicely, and set to “Brothers in Arms”, no less…
There was an episode of Homicide: Life on the Street where a guy was pushed off a subway platform in between two subway cars, and basically was stuck there waiting to die while the officers hunted for the pusher & the guy’s wife (girlfriend, maybe?) who was out jogging. Vince D’Onofrio was the pushed guy. Riveting television.
This is a bit of a stretch, but I was amazed at how they put this one together – ** South Park **, Christmas in Canada – a spoof on “The Wizard of Oz”, set in Canada, where they discover the new Prime Minister is none other than Saddam Hussein I’m impressed by this episode mostly because it’s damn funny but also because The news of Hussein’s capture broke on Sunday morning – this episode was written, voiced, animated, and put on the air by Wednesday evening .
That’ll be Time Keeps On Slippin’
Great quotes in this one!
Bubblegum Tate: “For generations your puny planet has lived in peace with the globetrotter home world, but now, for no reason, we challenge you to defend your honor on the basketball court. Will no one meet our challenge? Have none of you pathetic earthlings ‘game’?”
Prof. Farnsworth: “None too soon. While you were gone, the Trotters held a news conference to announce that I was a jive sucka.”
Bubblegum: “Who dares laugh at the jesters of dunk? We came to terrify and humiliate you, not tickle your funny bones! Watch as I embarrass your civilization by passing the ball to Curly Joe” spoing “Only to have it remain in my hands with elastic! Aaaahahahaha”
Marv Albert’s head: “Yeees! He’s really showing us what a man with a cannon in his chest can do!”
Oh, how I love this show.
Second for X Files: Jose Chung’s “From Outer Space.”
Other nominations:
South Park-the Christmas in Iraq episode. “Red sleigh down! We have a red sleigh down!”
Magnum PI “Did you see the sunrise?” Part 2.
“Ivan?”
“Yes?”
“Did you see the sunrise this morning?”
“Why yes, yes I did.”
BOOOM!
Millenium second season finale. (If there were any justice it would have been the series finale.)
Babylon 5 “War Without End” Part I and II.
Star Trek TOS: The Trouble with Tribbles.
I’ll second the episode “Jurrasic Bark” from Futurama. Never has a cartoon brought me as close to tears as I was from this episode. I have had two different girlfriends cry after seeing this episode. For those that haven’t seen it, the summary is as follows:
Fry discovers the fossilized remains of his dog, Seymour. The professor says he can clone the dog, and the dog can even have his old memories back, so he’ll know who Fry is (and still remember how to sing “Walkin’ on Sunshine” 
.) However, the prof. finds out the dog was fifteen years old when he died, and Fry got frozen when the dog was 3. Fry stops the cloning, saying that although he remembers Seymour, Seymour forgot him a long time ago. Cut to the past (aka 1999) to show to dog standing in front of the pizza parlor Fry worked at, because before Fry got frozen, he told him to wait ther etill he got back. We then see a series of scenes as time goes by where Seymour stays in that one spot, waiting for Fry to come back. We see the pizza parlor get crappier and eventually close, a tree gets cut down, seasons come and go, and still Seymour stays un that one spot until finally, he lies down and goes to bed :(. It doesn’t haelp that they play this sappy song. I don’t know the name, but the lyrics consist of “If it takes a sthusand summers, I will wait for you.”
Other noteworthy Futurama episodes include:
“Luck of the Fryish” - Fry thinks his brother stole his life and name when he finds a statue dedicated to him. It turns out
It is Fry’s nephew, named after Fry to carry on his spirit.
It also has one of the best Bender lines ever:
“There, now no one can say I don’t own John Laroquette’s spine!”
“The Why of Fry” - Fry saves the universe, Leela gives him a kiss.
“As Time Keeps on Slippin’”
“The Devil’s Hands are Idle Playthings” - The final ep. Turns into a musical at the end.
Two of mine are from Taxi:
The one where Latka brings in his grandma’s “special” cookie recipe that actually contains cocaine, “I’m gonna be famous, like the famous Amos.” And Amos actually comes to him in a dream. Brilliant.
The other is when Jim turns into Jim. He’s a college student and I think his roomie is Tom Hanks. Anyway, Tom blazes up a doobie and Jim is really square until he takes that first hit, which is when he turns into the Jim we know and love. Again, brilliant.
I hereby add my support for Buffy’s Once More, With Feeling, MASH’s Goodbye, Farewell, Amen, and ER’s Love’s Labor Lost. All incredible episodes. And a few of my own …
The X-Files - Bad Blood. Mulder and Scully do “He Said, She Said.” With vampires.
Blackadder II - Chains. If only for the pantomime with the Spanish Inquisition.
Angel - Birthday. How Cordy’s life could have been. And everybody loves Skip.
The West Wing - Two Cathedrals. The whole episode is beautiful and heartrending, and the early relationship of the President and Mrs. Landingham is just perfect.
Sports Night - The Six Southern Gentlemen of Tennessee. Comedies don’t often make me tear up. This one did.
Star Trek - A Taste of Armageddon. I can still remember the first time I ever watched it.
I have to go do work now, but I’ve got a list a mile long.
My absolute favorite of all the Star Treks was TNG’s “Best of Both Worlds”, parts 1 and 2.
Oh, wow. How could I have forgotten *Passing Through Gesthemene * - Babylon 5?
I love threads like this one. They serve to 1) remind me of some awesome episodes, 2) turn me on to some I might have missed, 3) allow me to laugh hysterically at the insane opinions of my fellow posters, some of whom have no taste at all! 
Well, I guess I’m going to have to be the first to nominate a Roswell ep here… “The UFO Convention.” Great ep, including a powerful guest appearance by Tom Bower as an alien hunter who’s lost everything except for his dreams of payback.
Also Buffy ‘Dopplegangland’, Angel ‘spin the bottle’, DS9 ‘Call to arms’ and Simpsons ‘Lisa’s wedding’
The New Twilight Zone - “A Small Talent for War”.
thirtysomething - The episode where Hope finds the diary from WWII.
Hill Street Blues - The episode (I don’t know the name) where a nun is murdered, and Furillo has to threaten to release the suspect (whereupon he will be lynched) to force a confession. The opening is riveting - Furillo sees the crime scene, turns to his people and barks a list of crisply efficient commands, then runs to his car and says to the driver:
Not the last episode of MASH - the episode where the war reporter is interviewing the characters. And Mulcahy gives the most haunting speech I have ever heard on TV:
Or any episode ever of Taxi.
Regards,
Shodan