This is a list of episodes that feature one of the characters leaving the show. For example, here's mine:

1. "The Person Formerly Known as Lowell" - This episode of "Wings" which happened early in the seventh season of the sitcom finds mechanic Lowell Mather pondering over his future. He witnesses a murder and has been threatened, but he feels he has to testify against the killer, which means he'll have to leave Nantucket and all his friends forever to join the Witness Prottection Program. He does and has a tearful farewell with the gang.

2. "Bobby Doesn't Live Here Anymore" - This episode of "Taxi" which happened early in the fourth season of the sitcom finds Bobby returning from California after giving acting a shot there. He comes back with hopes of landing a pilot, which he does, only to find out that he's been fired from the show. Alex convinces Bobby to go back to California, since it would be better for his career, than it would be staying a cabbie. Bobby says goodbye to his friends (and Louie) at the Sunshine Cab Company and leaves for California.

3. "Til the Next Goodbye" - This episode of "That '70s Show" which happened at the end of the seventh season of the sitcom finds Eric preparing to leave Point Place for Africa, so he can eventually become a teacher. Eric gets inside the Vista Cruiser with Donna and has to be pushed out of the driveway as he's shouting, "So long Point Place!" This episode was supposed to be Kelso's final show too, but he returned as a guest star the following season.

4. "Hello, I Must Be Going" - This episode of "Ellen" which happened early in the third season of the sitcom finds Adam with a job offer in London. He takes it and says goodbye to everyone. While saying goodbye to Ellen, he admits that he's in love with her. However, Adam soon learns that plans have changed and he has to stay for another week. The next week, Ellen lies and tells Adam she's in love with him too, to send him off happy. But then, plans change again, and he's there for another day. Finally, Ellen goes down to the airport to say goodbye to her friend the right way.

5. "Abyssinia, Henry" - This episode of "M*A*S*H" which happened at the end of the third season finds Lt. Col. Henry Blake getting all his points and being sent home. Hawkeye, Trapper and Radar have a farewell party with Blake, which involves them all getting drunk. The next day, Blake says his goodbyes to the gang at the 4077, and places Frank in charge (something that will change in the next season when Col. Potter comes). Later on, Radar comes into the O.R. with the devastating news... Henry's plane was shot down over the Sea of Japan. There were no survivors.

6. "Welcome Home, Parts 1 & 2" - This two-part episode of "Happy Days" which happened at the beginning of the eleventh season of the sitcom finds Richie coming home from the Army, along with Ralph Malph. Things are fine, until Richie tells his family that he wants to be a screenwriter. After a heavy episode, which includes Richie getting drunk and punching the Fonz, Richie decides to move to California and pursue his dream. The goodbye scene between Richie and Fonzi is very touching.

I also liked Ted's last episode of "Hey Dude" where he went on a date with Bradley, before telling her that he had to leave to go to Summer School. He came back towards the end of the series, though.

I totally agree about the Happy Days episodes. Richie would visit one more time, in the final episode, to attend his sister Joanie's wedding.

The Barney Miller send off to Fish was a highlight, but nothing could top the tribute episode the show did for Jack Soo (Yemana).