This is by far one of the most enjoyable animes i've seen in a long time. Following the popular idea of a girl having to pretend to be a guy at school, the show follows Haruhi, a 'commoner' at an elite school for the rich and powerful. After breaking an expensive vase, she must pay off the debt by working as a host in a club created to entertain girls. However, to do this, she must keep up the pretence that she is a guy. The plot lines are hilarious, with moments of sadness or sweetness thrown in. There are a few taboo-ish themes, like homosexuality, incest and rape, but they are dealt with in a non-confrontational manner, so it is unlikely a conservative viewer would be particularly offended by anything.
Particularly of note are the characters and their development throughout the series as we learn more about them. In the club is the 'Lord', Tamaki, a perceptive, empathetic leader who often comes across as a bit of an idiot (but there is more to him than meets the eye); Hikaru and Kaoru, the mischievous, incestuous twins who use their closeness to appeal to girls; Kyoya, the money-minded, enigmatic shadow-lord; Hunny, the loli-shota obsessed with sweets, and his loyal friend Mori, a silent, stoic type. Haruhi herself is bookish and immune to the charms of the guys, yet becomes entangled in a (very light) love-triangle, which is vaguely resolved by the end of the series. It's easy to relate to and fall in love with all of the characters, and OHSHC is one of the rare shows where you find yourself caring about every character, not just a few.
I would recommend OHSHC to anyone above the age of 13. It seems like a show aimed more at girls, but I gave it to my brother to watch and he loved it. I haven't read the manga (yet), so I can't compare; also, I hear that there will soon be an American-dub version released. As American dubs are notorious for their censorship, i have no idea how that might change the show (probably for the worse), so i'd recommend going and watching the original Japanese version with subtitles: the voice acting is pitch-perfect!
Particularly of note are the characters and their development throughout the series as we learn more about them. In the club is the 'Lord', Tamaki, a perceptive, empathetic leader who often comes across as a bit of an idiot (but there is more to him than meets the eye); Hikaru and Kaoru, the mischievous, incestuous twins who use their closeness to appeal to girls; Kyoya, the money-minded, enigmatic shadow-lord; Hunny, the loli-shota obsessed with sweets, and his loyal friend Mori, a silent, stoic type. Haruhi herself is bookish and immune to the charms of the guys, yet becomes entangled in a (very light) love-triangle, which is vaguely resolved by the end of the series. It's easy to relate to and fall in love with all of the characters, and OHSHC is one of the rare shows where you find yourself caring about every character, not just a few.
I would recommend OHSHC to anyone above the age of 13. It seems like a show aimed more at girls, but I gave it to my brother to watch and he loved it. I haven't read the manga (yet), so I can't compare; also, I hear that there will soon be an American-dub version released. As American dubs are notorious for their censorship, i have no idea how that might change the show (probably for the worse), so i'd recommend going and watching the original Japanese version with subtitles: the voice acting is pitch-perfect!