I'm bending the premise a little bit: The Boys is based on a graphic novel and bears almost no resemblance to the source material. I think the show is way more compelling and engaging than the graphic novel, probably because the show is written to be aggressively topical, while the graphic novel concluded over a decade ago.

I'm not sure about "better" but I would point to the IT and the Stand miniseries from the 90s that were excellent. Both books had parts that were problematic to put on screen, and a lot of fans felt the omissions were improvements. Also, the author was heavily involved in the productions, writing the scripts and consulting with the directors.

I don't think they make tv shows out of bad books, though, so I'm having a hard time thinking of other examples.

I cannot remember the details that led to this opinion, but I remember preferring the first season of Dexter to the novel that it was based on. I think that was the only season that was even close to a direct adaptation of the novels, but I liked the changes that were made.

Do comics count? The Walking Dead because it was way different and more creative. But I still like the comics.

The Fall of the House of Usher not only improves the original story, but beings many of Poe's works to life in a cohesive, beautiful way.

I'm also much more a fan of Flanagan's Haunting of Hill House than Shirley Jackson's, but I understand that's a controversial opinion about a widely loved book.

Altered Carbon.

Station 11. Its art. The book wants.

X-Men

Most Porn

The book's all sticky and it smells funny.

IIRC lemonade joe the movie was better than the book