I like a lot of the titles already mentioned, mainly Imadoki, Fruits Basket, and Absolute Boyfriend.
A Little Snow Fairy Sugar was cute. That was only 3 books.
I liked Alice 19th. (Same author as Imadoki, Absolute Boyfriend, Ceres, Fushigi Yugi.) It's 7 books.
Clover was pretty good. That's 4 books.
Magic Knight Rayearth is
It's only 6 books.
Onegai Teacher is good. It's 2 books.
If you like books, Read or Die and Read or Dream are good. Die is more action and Dream is more shojoish. They are both 4 books.
Sailor Moon is
but it's kind of hard to find now since the American licenses ran out. :/ It's 18 books altogether.
Guru Guru Pon-chan is excellent. It has one book left to be published and is 9 books altogether. I might put off reading the last book for a bit once it does come out because I don't want it to end yet. haha
I liked The Good Witch of the West anime and I'm enjoying the manga as well. It's 5 books altogether (3 are out).
I'm enjoying Kitchen Princess. It's a sweet story, plus it has recipes in the back.
lol It's 5 books (2 are out).
I just started Pixie Pop (3 books/2 out) and Shugo Chara! (3 books/1 out) and I'm enjoying them so far.
If I could pick one out of all of them to recommend, I think I would pick Guru Guru Pon-chan. It's one of my current favorites. I hope I was some help!