harem is like the easiest genre to find in anime Xd but good ones are hard to find I'll just list some and you can check them out
Ai Kora
Air
Amaenaideyo!!
Angel Tales
Angel/Dust Neo
Tenchi Muyo!
Tenchi Universe
Tenchi in Tokyo
To Love-Ru
Tsuki wa Higashi ni Hi wa Nishi ni: Operation Sanctuary
Tōka Gettan
D.C. II: Da Capo II
D.C.: Da Capo
DNAČ
Dears
Dual! Parallel Trouble Adventure
Nagasarete Airantō
Negima!: Magister Negi Magi
Saber Marionette
Sakura no Uta
Shuffle!
Sister Princess
Strawberry 100%
H2O: Footprints in the Sand
Ef: A Fairy Tale of the Two.
Little Busters!
Love Hina
Kanon
Hand Maid May
Happiness!
Happy Lesson
Utawarerumono
Kanon
Also the best reverse Harem ever
Ouran High School Host Club
honorable mention to
Fruits Basket
Fushigi Yūgi
