Umm lets see...most of these are going to be manga :)
Manga
-AH! ITOSHI NO BANCHOUSAMA ( its really cute like Host Club and it has a "mommy" figure and its surprising that the mommy figure is in a gang :p but there's a cute romance and i know ull love it http://www.mangafox.com/manga/ah_itoshi_no_banchousama/ :)
-SAILOR FUKU NI ONEGAI! (it has action like fruits basket and the gaudians can chane from being a human to being a dog and ull see what else :) more romance (bt cute ;) in this one than Host Club or Fruits Basket http://www.mangafox.com/manga/sailor_fuku_ni_onegai/ :)
-HIIRO OUJI (vampire based like Karin but has a twist to it. Right now only 2 chapters http://www.mangafox.com/manga/hiiro_ouji/ :)
-HEART NO KUNI NO ALICE (this one has MANY colorful characters with there own diff personality like in Ouran and Fruits basket http://www.mangafox.com/manga/heart_no_kuni_no_alice/ :)
- S.L.H ( This is the closet thing to Ouran i have read :D Characters are awesome and its just soo cute ^-^ http://www.mangafox.com/manga/s_l_h/ :)
-CHARMING JUNKIE ( Naka is just like the main girl from Fruits Basket http://www.mangafox.com/manga/charming_junkie/ :)
-OTOKOMAE! BEADS CLUB (ouran tyoe characters (crazy ppl i got to say :) with more romance and a strong chick http://www.mangafox.com/manga/otokomae_beads_club/ :)
-OUJI TO MAJOU TO HIMEGIMI TO (Like Ouran also but a VERY big twist http://www.mangafox.com/manga/ouji_to_majou_to_himegimi_to/ :)
-SHIAWASE KISSA SANCHOUME (the chick is sooooooooooo cut!!!!! you WILL absolutely LOVE HER!!!!!!!!!! And her two friends are sooooo hot T-T haha well cut hilarious manga that u will love http://www.mangafox.com/manga/shiawase_kissa_sanchoume/ :)
-RENSOU NO ARIA (hahaha im just throwing this one in cuz the guy is sooo hot XD http://www.mangafox.com/manga/rensou_no_aria/ :)
-Bloody kiss (Like Karin (vampire stuff hehehe its down in the sources :p
-Hanatsuki Hime (this manga is a bit more magical than the ones uve listed but the story love and art are to die for!!!! the ROMANCE!!! ahahahah T-T
-NOUSATSU ROCK SHOUNEN (kinda randome also but its totally AWESOME!!!!!!!
-ORESAMA TEACHER (its a gender bender but in a way it also has colorful characters like Ouran and its supper funny!
well i hope i gave u some that u liked :D