Episodes you actually get emotional over..

[Bruce Banner]

Serina's death in Battlestar Galactica.

[Spawn67]

Another one that always does it for me is the "Moving Out" episode of Laverne and Shirley in there final scene at the classic apartment right before they move to California. Humorous yet sad at the same time (The show should have ended after this episode in my opinion)..

https://www.youtube.com/watch?v=tk7s9IHo9nI

[Drzsmith]

Family Ties when Alexs friend died also All in the Family when Edith was raped.....very sad.

[Allie Fox]

The new Battlestar Galactica when Col. Tigh had to kill his wife for being a traitor.

[HardyGirl]

For sitcoms: I agree w/ Hector about Good Times where James dies. That's a good one. And where Penny is abused.
In one ep of Growing Pains where Carol's boyfriend who's been in an accident dies.
In the Family Affair ep where Buffy and Jody have a little friend who dying and they celebrate Christmas early for her.

And I love the Waltons too, as well as Little House on The Prairie.

In other series: Highlander where Tessa dies, and pretty much any episode of the first 2 seasons of Beauty & The Beast (80s series).

[Nostalgiabuff]

Smallville when Jonathan Kent dies. Definitely the MASH episodes mentioned.

[nvmbrsdoom5]

The first thing that came to mind for me was the episode "Married" from Season Two Episode One of "The Incredible Hulk" 1978 series. This series was never exactly a happy ray of sunshine at any point, but that particular episode was very sad to me. I watched it (alone I might add) when it first aired and I was only five years old. That episode in particular was just a bit too heavy for me to understand, and it haunted me for a long time. Particular the bit with Banner's nightmare sequence, with the reaper on the bus etc. It made me cry then because it was scary and I didn't understand. Now that I'm older, I understand the episode completely, and it doesn't scare me but still makes me emotional because it's so sad.

Another long-time favorite that makes me a bit teary at the end is Star Trek "The Menagerie". It's still hands down my favorite Trek episode, and probably my favorite thing Trek related overall. The Pike and Vina story is great, very moving at the end.

In regards to more modern shows, I can't think of any primetime sitcoms that've moved me like that but the final episode of "Six Feet Under" was one of the most moving things I've ever watched on television. Incredible ending.

[rykerw1701]

Star Trek TOS when Edith Keeler dies always gets me. MASH when it's announced by Radar that Col. Blake's plane was shot down. And on Big Bang Theory when Bernadette revealed she was pregnant. Because you know that's the Jump the Shark moment for the show.

[Gorn Captain]

On Buffy, when Spike, after a century of evil, finally sacrifices himself to save the world (and Buffy), and goes into the void triumphantly, as a hero.

[Gorn Captain]

There's an episode of Hill Street Blues, when Joe Coffey, big guy with a heart of gold, walks into a grocery store and gets blown away by a robber. Like Coffey himself, you never see it coming. Bang, and gone. It leaves you shocked.

[johnmiic]

Some epsiodes of SCRUBS like when Laverene was taken off life support and Carla had to say goodbye.