Tear Jerker / 3rd Rock from the Sun

• Don's utterly heartbroken in "Sally Forth" when Sally reluctantly declines to marry him because she's not ready for such a commitment. Wayne Knight does a great job acting in that scene.
  Don: Ah, Sally. You're like this beautiful wild horse. If I'm gonna keep you, I'd have to break you. Because if I didn't, you'd just keep throwin' me off and steppin' on my head. But I don't want to break you, Sally. I love you. So I guess I'm gonna have to let you go. If, uh if someday you should choose to, uh, come back to me, maybe I'll be here, maybe I won't. We'll just have to see.
  Sally: So this is it?
  Don: (holding back tears) You know my number.
  Sally: Hey, Don. Can we turn on the siren? You know, for old times' sake?
  Don: Sure.
• When Tommy asks Alissa to marry him in the episode "Near Dick Experience" she eventually says yes, but by then, Tommy has changed his mind and doesn't exactly break the news gently, leaving Alissa on the verge of tears.
• Sally is unusually introspective at the end of "Selfish Dick" when she comes across the maternity ward full of new babies:
  Sally: Aw! Shh! Don't cry, sweetheart. This part's easy. Just wait till you have to choose a long distance carrier. I wish I could have started from scratch like you guys: Knowing, but not knowing. Seeing, and then all at once forgetting. Enjoy it. Time here moves really fast.
• The final episode, "The Thing That Wouldn't Die, Pt. 2," where the Solomons reminisce over everything they'll miss about Earth, leading to Mary realizing at the last second that she just can't leave her life behind for Dick.
  • "Dick, I'm leaking." Funny a few years back, tear-jerking at the end of the show.
  • The moment when Tommy, who'd been annoying the others with his flippant attitude about leaving, suddenly breaks down in tears, sobbing like a little kid and admitting he doesn't want to go.
  • The looks on Dick and Sally's faces when they find out the mission is over are heartbreaking.
• "A Nightmare on Dick Street, Part 2": the Solomons have experienced dreams for the first time ever, but they think this means they're going crazy and have to return home for emergency maintenance. Dick ultimately decides to stay with Mary and marry her, much to the others' displeasure. They reluctantly go their separate ways, but after talking to Mary, Dick learns that dreaming is a normal part of the human experience. He races home to tell the others that no one has to leave, only to find the apartment empty.
  Dick: HELLO?! SALLY?! HARRY! TOMMY?! [finds a note] "Dear Dick, of all the people we've worked for, you were the best... you stupid, stupid man." They're gone, and I missed them.