1) clannad
2) angel sanctuary
3) chobits
4) Dn Angel
5) love hina

None of these are in any order, and I have a bunch more. These are the ones I can think of in such a short time. Sorry, but some of them are manhwa.

Bitter Virgin: This is one of the most original, non-cliche series I've read. The plot is sad, and the things that happen throughout the story are even sadder. Even though the main character is shy, etcetera, the story is really hooking. People can really relate.
Hatsukoi Limited: The art is so cute...! And all the stories/characters are so interesting.
Yuuhi Romance: Uh... I like incest. xD; The main character is really hilarious.
The Flower of Evil: I like twincest too, haha. This story is a bit different, though... the way Se-Wah acts is really interesting, and the story progresses well. I love the art too daskdlas.
Vanilla Ice: Genderbenders are awesome. xD I like Never Give Up! and Hush, too.

Hana Kimi
Desire Climax
Love Monster
Kaikan Phrase
Cherry juice

1. Suzuka
2. Parallel
3. Pastel
4. Kagetora
5. Salad days

1. B.O.D.Y.
2.Binetsu Shoujo
3.7th period is a secret
4.Faster than a kiss
5.your my girlfriend

Hehe there are really many XD but ill tell some
1. Love Monster ( SPOILER ALERT first i thought it was kinda too much ecchi but then it was only romantic and really funny too XD )
2.Saboten no himitsu ( hehe really cute)
3.Moe Kare/Uwasa no midori kun (the character looks the same ( almost) but it has different story plots)
4. B.O.D.Y. ( SPOILER ALERT haha i mean you fall in love with the host and then he falls in love with you and dont wanna give up XD)
5.Kamichama Karin and the season two Kamichama Karin -chu- ( i mean really funny kids love SPOILER ALERT but then they really arent kids and the married lond time ago XDhaha and all with the gods of greek like zeus and so on)
soo...that are some now here when you all read those :
6.Love berrish
7.Chocolate Cosmos
8.Happy Hustle High
9.Cherry Juice
10 Fall in love like a Comic
11. Gakuen Alice ( omg i almost forgot that- now that i think about it this is my number one XD )
So if you want more, feel free to ask me! ;)

Loveless
Ranma ½
Midorino hibi
Fruits basket
and rurouni kenshin

Shinshi Doumei Cross?
Loveless
Special A
Backstage Prince
Ouran

Skip Beat
Absolute Boyfriend
Paradise Kiss
Nana
Shinobi Life

My top 5;
Saiunkoku Monogatari
Love Monster
Vampire Knight
Bakura Ga Ita
Ghost Hunt

--Vampire Knight
--Hana Yori Dango
--Hot Gimmick
--Zettai Kareshi
--Ayashi no Ceres

--not in any particular order...

1. Hana Yori Dango
2. Hana Kimi
3. Kaikan Phrase (Sakuya makes me drool)
4. Nana
5. Fruits Basket

*not in any particular order~

I tink fruit basket overall was gd..
n.....Vampire knight...n others...dun quite rememeber..

absolute boyfriend
kare first love
hana kimi
lovely complex
bitter virgin

:)

1. Shinshi Doumei Cross
2. Vampire Knight
3. Special A
4. Boku no Hatsukoi wo Kimi ni Sasagu
5. Hana Kimi

but i like a lot more! <3