Buffy the Vampire Slayer is a great show, and someone who likes that sort of show, should give it a try. That's about as far as I can go with a recommendation.

A TV show can never be rewatched for the first time. A good story has character growth, so Dawn doesn't remain a pain-in-the-ass little sister and Tara can do more than sheepishly mumble. They both eventually pay off. The viewer doesn't know that the first time through. Last summer, I watched Lost for the first time. Rewatching would be a different experience.

Also, you are in a different point in life. I tried watching Breaking Bad when it came out, but it didn't take because it was too intense. A few years later, I got into it.

GOAT lists are all flawed. When I see a GOAT list, if I've seen five of the shows on the list and really enjoyed them, then I might try the other fifteen shows on the list.

Buffy the Vampire Slayer certainly deserves a place on many people's list.