Basically:
-it was my gateway anime, without it I most likely wouldn't have got into anime
-Usagi's portrayal and the rest of the characters (except chiba, I don't mind Minako being an usagi clone but I prefer her portrayal in the manga/crystal/pgsm )
-Villains usually lasted longer (and some were turn good, it's a shame they were forgotten a season later, I would have liked to see the healed spectre sisters hang out at Rei's temple during S for example)
-transformations were fun to watch
-Naru x Nephrite
-Kunzite x Zoisite
-Moon/Mercury/Mars trio in classic
-Fillers (some were good and funny)
-Animation in SuperS
-Music and BGM were the perfect
-2 of the 3 movies
-Rei/Usagi arguments were amusing but Chibiusa/Usagi ones annoyed me
-The friendship and closeness of Rei and Usagi
-Hotaru and Chibiusa's friendship
-DD Girls
-The ending in classic, it was very emotional and perfect in my opinion
-the Ali-en arc
I could go on
I love the 90s anime very much