Just pick one!
With all the Carol Danvers hype, I rewatched "A Rogue's Tale."
Best episode of the series! Great voicework, drama, and tragedy.
Maybe the best ending of series with Rogue at her hospital bedside and the small smile showing the power of forgiveness. The best and most unique episode of that great old series.
This episode made Ms. Marvel intriguing and mysterious to A LOT of non-comic book readers who had no idea who she was. This was pre-internet, so you couldn't wikipedia the backstory.
The one where Kitty appeared. Oh, wait! She didn't. EVER! Yup, still bitter.
Not a fan of the series, but the "Days of Future Past" 2-parter would be mine.