The official description to the English version of novel 4 labeled Yuki as a time-traveling robot...which is technically true...very technically: She doesn't physically travel through time, but can control it locally and can sync with past and future versions of herself, and while she is a construct, she's still biologically human.
The description on the back of the English version of Melancholy says that Kyon sits behind Haruhi in class, which has never been true.
The blurbs of the English releases seem to have a penchant for this trope, as the summary on the back of novel 7, Intrigues, is almost 100% wrong. It says "When Kyon discovers that something's not right with the universe, it's up to him, ...Mikuru, and... Nagato to head back to the past in order to save the future." This is NOT at ALL what happens in the book, instead it's about a version of Mikuru from 8 days in the future coming back to what would be the present for Kyon. Hell, Kyon even flat-out says near the beginning "This time, it wasn't me who traveled through time. I didn't take a single step outside of my own present moment." The only thing it could be referring to was the prologue, in which he briefly goes over the events that happened between it and and the short story "Where Did The Cat Go?" from Wavering, specifically when he goes back to save the version of himself in the past from the end of Disappearance. But the prologue is only 22 pages out of a nearly 300-page long book.
Dawson Casting: Haruhi's English dubber Wendee Lee, one of the Streamline Pictures generation, is 51 as of Disappearance (which was released on DVD and Blu-ray on September 20, 2011). In fact, she's the only SOS Brigade member to be voiced by a Streamline veteran.
Image Song: Every named female character (plus Kyon's sister), Kyon, Itsuki, and Taniguchi have either one or two, plus a personal rendition of the Dancing Theme (though not Taniguchi, who was second season only). It's a little ridiculous.
The 2004 manga was only released in Japan, and only saw a limited print run, to where a physical copy is hard to find even with the help of the internet. The artist of this particular iteration got fired, either due to the artist drawing and selling unauthorized Hentai for the series he was drawing for, or the artwork seen in this series being less than stellar (most likely the latter). Either way, the publisher would rather forget it ever existed, going as far as to commision a completely new manga series to another artist rather than reprinting this one once the Anime got popular.
Series 1 of the anime The Melancholy of Haruhi Suzimiya seems to be heading towards this in the UK- it's maybe possible to pick up copies second-hand but not new. Oddly enough, Series 2 is easy to find as is The Disappearance of Haruhi Suzumiya and The Melancholy of Haruhi-chan Suzumiya.
Expect everybody to buy four DVDs of said. To say nothing of the DVD volume numbering gagnote "Endless Eight" begins at volume 2, with each successive volume simply using larger decimal places without actually reaching the next whole number, which just comes off as condescending.
Hint at an "Endless Eight" movie.
Win every single fan back with a 30-second, unanimated commercial.
On December 18, 2013 (Japan time), a Firefox error message containing hidden text including "The Disappearance of Yuki-chan, docomo android" replaced the front page. If one were to visit the site on an Android device...
Since 2009, the site features the list of activities from "Endless Eight" every year, from August 16 to mid-September. Before August 31, the list's length varies each time the page is refreshed, due to some events being left out in-universe in certain iterations. A recording on Aug. 30 (from 2012; applies to any given year) is demonstrated here.
Originally, Kyon was going to be an esper, but Tanigawa felt that Melancholy worked better with him as an ordinary student.
Dub only: For the second season's Endless Eight arc, Bandai considered turning it into a Gag Dub, with the voice actors switching characters, or doing each episode with a different accent. Unfortunately, they decided to do a straight dub instead, even though Crispin Freeman gets to improvise some lines.