Ones that i've read/reading:
Skip Beat
Kaichou wa Maid sama
Ojousama's Orders
You're my girlfriend

Don't know if this helps but i also watched these animes:
Ouran High School
Special A
Fruits Basket

Hopefully someone can give me suggestions because i don't know what manga to read
thanks

i know a few, but they aren't Shoujo, is that ok?

yup thats fine

koukou debut

might work....

Yotsubato! Minus the High school part
Ai Kora
Happy World!
Mahoromatic Kinda
Cromartie
Angel Densetsu is really good, story wise and comedy wise.
Midori no Hibi

....i thought i had more since i mainly read comedy...but i guess that's it from me.

Did you know you can use the genre search function to look for manga with those requirements? search genre

Here are some suggestions:
Hana Kimi
Beauty Pop
H20
Lovely Complex (and others by this mangaka)
Matsuri Special
Akuma de Sourou
Gokinjo Monogatari
Hana Yori Dango
W-Juliet

The three animes you mentioned also have manga, which in my opinion are way better than their animated counterparts.

I'd say read the manga versions of Ouran High School Host Club, Special A, and Fruits Basket.

I''ll also recommend;
Parfait Tic
Kare First Love
Shinshi Doumei Cross
Saboten no Himitsu
Rockin' Heaven
Koko ni Iru yo!
Love Berrish!

And then there's this thread. (:

EDIT: I think you can find a lot from the above posts && the thread I've mentioned, so lock kay? :3