Sometimes there comes along a single episode of tv from a series, that isn't necessarily a premiere or series finale, that overwhelms me and causes me to remember it for a long time and try not to miss it when it is repeated in syndication.

One such episode that I absolutely love and always tape when it comes back on is:

"On the Beach" ...ER from Season 8 (2002). It is Dr. Greene's (Anthony Edwards) last episode and that rendition of "Somewhere Over the Rainbow" by Israel Kamakawiwo'ole gets me every single time. I think i love it more for the song than anything else.

Also, though it is a finale, "Everyone's Waiting" ...Six Feet Under last episode ever from Season 5 (2005) was one of the best episodes and series finales i have ever seen.

What's yours?

Exodus, Part 2 from Battlestar Galactica - movie-quality action, a great story, exciting from beginning to end. I LOVE that episode.

Lost: The Pilot
Six Feet Under: Everyone's Waiting

Buffy the Vampire Slayer: "The Body"

If we aren't talking about a pilot or finale or some kind, this was the first one that came to mind for me, too. I also thought of Hammer Into Anvil from The Prisoner.

My 5 favorites just off the top of my head:

Six Feet Under - "Everyone's Waiting"
Buffy - "The Body"
Lost - "The Constant"
Buffy - "Hush"
The Office - "The Injury" (had to get a comedy in there)

Mad About You - Natural History
Don't know why, but this episode gets me every time. Jamie and Paul argue because they have different plans for the weekend and can't spend their time together. Later a chance meeting at the Natural History Museum recalls an earlier time in their lives which could indicate that their being together might not be chance at all.

X-Files - Clyde Bruckman's Final Repose
The best single episode of the X-Files run, manages to send up, transcend and deepen the concept of the show all at once. Peter Boyle will always be Raymond's Dad, or The Monster in Young Frankenstein to others, but he'll always be best remembered to me as Clyde Bruckman.

Gilmore Girls - Emily in Wonderland
Excellent season 1 episode filled with all the witty dialog you'd expect, plus it puts Emily in Stars Hollow for the first time and you see her both in and out of her element. Then when she sees where Lorelai first lived when she was raising Rory, you get a feel for Emily's pain as she realizes that she pushed Lorelai away years ago, made her struggle to be successful and lost seeing a whole section of Rory's life.

Homicide - "Three Men and Adena"
After a long investigation into a child's murder, do Pembleton and Bayliss have their man? And if so can they get a confession out of him? Spend a whole hour in "the box" with these three men and find out for yourself.

Moonlighting - "Atomic Shakespeare"
Completely diverting from the standard detective episode, the cast appears in a Shakespeare play, only with all the jokes, the fast talking, visual gags and breaking of the 4th wall that we've come to expect from this show.

WKRP in Cincinnati - "Turkeys Away"
"As god as my witness..."

What he said. But as far as episodes that aren't season/series premieres/finales (since those episodes tend to be the best of the season) I would choose:

Lost: Greatest Hits.
How I Met Your Mother: Slap Bet
Entourage: Vegas, Baby, Vegas.
Scrubs: My 15 Minutes

I can think of a bunch more from Scrubs and Entourage but I can't think of the names of the episodes.

I love Six Feet Under's finale and a lot of people mention that one so I'll mention a different one from the show - I'm Sorry, I'm Lost. An amazing episode from start to finish but the finale 15 minutes are just plain awesome. Oh and also All Alone.

Sopranos' Long Term Parking is another.

Newsradio: Daydream

X-Files Home

Beat me to it!

Supernatural's "Mystery Spot"
I wasn't into reusing such an original story from "Groundhog Day" but they pulled it off.

Futurama's "Jurassic Bark"
Anybody that has owned a loyal dog and doesn’t tear up watching this isn't human.

X-Files' "Home"
This stands out because I remember my jaw kept dropping while watching this. I'll never hear that Johnny Mathis song again without thinking about this episode.

Well I don't think its fair to include pilots and series finale's. So I would have to say either Gilmore Girls - "Raincoats and Recipes" or ER "On the Beach"

There are so many:

Babylon 5 "Sleeping in the Light" was the perfect ending to a great show and marks the first time I've ever cried watching a TV show.

Buffy: "The Body" already mentioned.

Homicide: "Three Men and Adena" already mentioned but "The Subway" and Fallen Heroes" deserve mentions as well. I will never forget the WTF moment when Jr. Bunk opens fire in the squad room.

Star Trek DS9: "The Visitor" marks the second time I cried watching TV. Seeing Jake lose his dad over and over again was just heartbreaking.
"Far Beyond the Stars" features some of the best acting ever. The fact that Avery Brooks directed the episode in addition to being in almost every frame blows me away.
"In the Pale Moonlight" a very dark, non-Trek episode as we see the lengths Sisko goes to defeat the Dominion.

ST Next Generation" Could go with "The Best of Both Worlds" but "Inner Light" features an amazing yet quiet performance by Patrick Stewart.

Studio 60: "The Christmas Show" even though the series itself was uneven, this episode was hilarious and touching with its tribute to New Orleans.

The Unit: "Play 16" usually when shows kill off an important cast member, by the next episode everything is back to normal. This episode highlights the fact that death has consequences on everyone.

West Wing: "Two Cathedrals" because nothing beats Martin Sheen in the National Cathedral cursing God in Latin.
"In the Shadow of Two Gunmen Pts 1 & 2" and "The Midterms" I usually do not love flashbacks but seeing how everyone met and the aftermath of the assassination attempt was done very well. The scene were Barlett explains to Toby why they can't get over what happened was powerful

X-Files: "Clyde Bruckman" was already mentioned so I'll throw out "Bad Blood." It's still an X-File but with some great humor and character moments. Duchovny singing Shaft is just hilarious.

No surprise, I'm sure... Lost - "Through The Looking Glass"

Married With Children's first Christmas special "You Better Watch Out".

Santa's chute does not open and he lands into the Bundy's back yard. This is one of few Married With Children that ends happily for Al.

buffys "hush" and "the body"

anyone that says the show is crap should be shown these two episiodes. I couldnt believe they didnt win an emmy for best drama in season 5.

Alias - Phase One

Buffy "Hush"

ER "Love's Labor Lost" (I'm not a big ER fan)

X-Files "Ice"

Seinfeld "The Soup Nazi"

Star Trek:TNG "The Measure of a Man"

Star Trek:TOS "City on the Edge of Forever"

Dawson's Creek: Pilot

The Office (UK): Training (where David constantly interrupts office training)

Ed: Captain Lucidity (where Ed has a Lucid dream)

Misfits of Science: Pilot (at least this was my favorite as a kid...probably wouldn't hold up today!)

Arrested Development as a whole had the best overall episodes as a series though.

Stopped watching ER after that episode. It seemed like a good time to stop and that was an incredible ending. The music was perfect.

Marge vs. The Monorail from The Simpsons would be my pick.

Twin Peaks: Pilot

Battlestar Galactica 33