--Five Spoiler-Free Reasons Why You Should Read the "Fruits Basket" Series--

1. Characters.
The characters are really wonderful. There is a large cast of characters in this series, and yet Takaya gives each of them (not exaggerating here) a great amount of depth. Readers will become personally invested with all of the characters in this series.

2. Story.
Although the publisher puts this series in the "romantic comedy" genre, it really doesn't fit neatly into any specific category. I was quite reluctant to read this series because the label said romantic comedy, and well, I'm not very fond of romantic comedies, to say the least (I much prefer some dark, gritty action and violence :]). Takaya herself describes the series as a sort of "domestic drama", which is a pretty good, though not all-encompassing way to put it. This story has moments that are hilarious, touching, heartbreaking, and uplifting. It'll go from being really funny in one chapter to really dark in the next. It's a story that was written for the sake of being a story (if that makes any sense), without worrying about fitting it into any particular genre/category.

3. Complete, focused series.
This series is short (for a manga series, that is), only 23 books long. Everything that happens in the books is important by way of characterization, character development, and plot. This is not an ongoing series, in which the author keeps writing books as long as they keep selling. With how popular this series was/is, Takaya could've dragged the series out a lot more if she had wanted to (much respect to her for not doing that though).

4. Better than the anime.
If you liked the anime, you'll love these books (but watch out; if you read it, it might lessen your enjoyment of the anime). I liked the anime, but the manga really is much better in my opinion. The characters are all a lot deeper in the books (as usual :P). I think that Tohru in particular comes across as a bit "preachy" in the anime (though not at all in the manga). The story is also incomplete in the anime, since it only goes through the first eight books or so.
~4a. Side note about scanlations.
I wouldn't recommend it. When I first became interested in the series, I tried finding some good fanscans online, but the only ones I could find were riddled with confusing and inaccurate translations. If you want to read this series, but money is an issue, then I'd look for used copies of the books. Keep an eye on Amazon and Ebay for some good deals on used copies (that's how I got my set).

5. The hype is there for a reason.
I was hesitant to try out this series because of all the hype around it. But hey, in this case, it's there for a reason. You should give it a try if you're at all interested.