I don't know if I can come up with ten but I'll try
Dawson's Creek S3 finale: Pacey and Joey leaving town together on a boat for the summer. So romantic and a nice payoff to all the bs Pacey had to go through with Dawson's douchey behavior and Joey's stand off ness after their relationship was exposed.
Scandal S3 finale: Jake and Liv leaving town together. Wow, another similarity to Pacey/Joey. Both couples have similarities to me that I've been noticing for a while.
Buffy S2: Sad ending for Buffy since she killed Angel, got expelled from school, her mom kicked her out, Buffy leaving town, etc. When it came on recently on ABC Family it reminded me how heartbreaking it all was. That's not something a 17 year old should have to go through.
Buffy S5: Buffy dying, just *cries*
Buffy S7: It's the final episode but it went out with a hell of a bang. Nice when a show can go out at it's peak instead of just beating a dead horse.
Dark Angel S2: Another series finale (cause Fox cancelled all the great shows smh) but the episode is so freaking good, I think James Cameron directed it himself, it was 90's minutes, it was so EXPLOSIVE. Just pisses me off they cancelled the show and that episode left so many things left hanging and unanswered
Daria S4: After everything with Tom and Daria happened your left wondering, "What now?"
Power Rangers in Space S6: Zordon's death, final battle, all the evil being defeated, Zedd, Rita, and Devatox turning good, etc.
Charmed S3: Bittersweet episode since it's the last with Prue but the witches being exposed, Piper getting shot and dying, etc.
Tru Calling S1: Tru saving Harrison but her boyfriend dying instead, the lines really drawn between Tru and Jack, it being revealed her father was helping Jack, etc. Another Fox show cancelled too soon