There is only one official word that comes to my mind when I think of Cardcaptor Sakura: Beautiful.
Everything about it is simply the epitome of beauty. The story, the characters, the art.
It's a CLAMP cult classic, and perhaps one of the most famous mangas ever written.

You think you know magical girl manga? Well, you haven't seen ANYTHING until you've read Cardcaptor Sakura. As far as your concerned, this is the ultimate magical girl manga. This is what inspired 100's of other artists to rip off the idea.
(Oh, and as I usually say, the Cardcaptor Sakura Manga is waaaay better than the anime. So don't even think that you shouldn't read the manga series, if you've already seen the show)

Let's get started, shall we then?

Story:
Sakura Kinomoto is a do-good 10 yr old who finds a mysterious book in her father's library entitled " The Clow". Upon opening the book, Sakura discovers that The Clow is in fact not a book, but a container to a host of 19 magical beings who were originally sealed in "Clow Cards". As well as releasing the cards, Sakura also releases the guardian of The Clow, which appears as a plushie like animal with wings, whom Sakura nicknames "Kero". Kero tricks Sakura into becoming the next "Cardcaptor" after sensing that she had magic in her. And so begins the adventure of Cardcaptor Sakura, but collecting the cards is only the beginning.

Art:
CLAMP's art is always breathtakingly beautiful, so it's no exaggeration when I tell you that I have never seen anything more amazing than the art in Cardcaptor Sakura. Some of the designs for the outfits Sakura wheres while "Cardcapting" are so original that it begs the question "where did they come up with this stuff?". CLAMP is truly the best of the best, the creme of the crop.

Characters:
Throughout the manga, one has to just fall in love with Sakura and her optimistic views on life. Her character is developed very well throughout the series, and each volume she starts to look more and more amazing than the last. The Clow Card designs are equally as wonderful to look at, and leaves the reader anticipating what the next one will look like.

Enjoyment&Overall:
If this manga was a person, I would marry it. So yes, to answer the question "If you love it so much, why don't you marry it?", I would. I most definitely and without any hesitance, would.
Cardcaptor Sakura is like a nice batch of fresh-baked cookies, but for your eyes. And what always gets me is that it's not just the art that makes this manga great- it's the fact that it manages to keep a well-thought out plot with plenty of questions and mysteries to keep the reader going.
I truly and from the utmost pit of my heart, suggest that you give this manga a try.
Thanks for reading.