Works That Are Adapted Frequently, But Still Don't Have a Really Accurate One?

So over the weekend I saw the new 3 hour French film version of The Count of Monte Cristo. It's pretty good, but makes some sort of weird adaptation choices I didn't care for. But that got me thinking, that book has dozens of film and other versions of it, but I haven't seen a really accurate version of that story. I hear good things about the BBC version from I believe the 60s, but I haven't tracked that one down.

Another example is Dracula. Bram Stoker's book has inspired probably even more versions, but no matter how much I like the Universal and Hammer classics, they bear only a passing resemblance to the novel. Even Coppola's supposed "most authentic version" is wildly unlike the novel, especially the whole reincarnated lover thing (which I hate). Poor Johnathan Harker gets really shafted in these adaptations. Once again, I hear good things about the 1970s film version directed by Jess Franco, starring Christopher Lee, but considering it is Jess Franco, I doubt it is THAT accurate.

Anyone have any other examples?