Hana Yori Dango is the first shoujo manga I read, therefore it always hold a special place for me. If you have seen the anime or any of its drama adaptations, you should definitely check out this manga as well.
In the times when feminism is yet to conquer Japan, Makino Tsukushi (the heroine) retaliates against the F4's bullying. Yes, I'm aware that she doesn't have the fighting skills of Wonder Woman but what makes her strong is the strength of her spirit. She's spunky, independent, hard-working, refuses to be a subject of social humiliation and stands up for what she believes is right - traits that, I believe, perfectly define her as a "weed." And yet, despite all this, Makino has a warm and forgiving heart and sees people the way they are. It's true that she had her own moments of weakness but that just makes her more human and realistic in my opinion. However, the bullying part only covered like 20% of the manga - and the rest is your typical shoujo/romance plot between a rich troubled guy and a poor plucky girl.
And because of this, I'm not surprised at the number of readers who complain about how cliche it was. This manga is supposed to be a CLASSIC and since it was the best-selling shoujo manga of all time, it's no wonder that it's one of biggest inspirations from all the cliches you've been reading in the mainstream shoujo titles now.
But what makes this manga stand out for me are the CHARACTERS. Each of them are multi-faceted and well-rounded and for that, I was too emotionally invested with them more than the plot. They have their good and bad traits that you can actually love or hate them as the story progresses on.
Perhaps there are even a few people aware of the fact that Hanadan was Yoko Kamio's "experimental" work. Back then, she planned to make Makino end up with Rui - which explains why the Domyouji/Makino ship doesn't seem like a "match made in heaven" in the earlier volumes and "doesn't seem right" for super feminists.
But since the mangaka changed ships, transforming Domyouji from a mess to a human being (so Makino will change her opinion about him) became the basic premise of Hanadan - and I believe that it's one of the biggest strengths of this manga.
Both the character growth (especially that of Domyouji) and how the pairing development was handled is quite impressive. Every mistake and transgression he caused her, he pays for it a thousandfold. How he does it? Words of apology are the hardest things to come out especially from a character who has the biggest pride in this manga - but he did show it by RISKING HIS LIFE for her a lot of times. Not to mention that he has to undergo one hell of an emotional rollercoaster just to win her over. He suffered as much or even more than she does. I wouldn't date a guy like Domyouji in real life but since Makino is a character neither me or you can insert yourself into, I believe he and Makino suit each other well.
The change wasn't one-sided since you get to see that happen in Makino as well. Throughout the course of their relationship, they both became mature and better people. If you compare Domyouji in the beginning and in the end, you get yourself two different people. And not just Domyouji, you can also see how much influence Makino brought to the rest of the F4 as well.
As for the art, I'm probably part of the minority who wasn't bothered by the earlier style since I began reading this during the 90's. Trust me though - the more you read, the more you see how much both her art + story-telling improved.