tdalton,
Even if i agreed that CR wasn't a great adaptation of the novel, it is still a far far better adaptation that any of the other movies (with perhaps only FRWL coming close, but that movie threw out the great high concept first part of the novel and the breathtaking cliff hanger ending).
However, in CR i personally feel they did a good job keeping so much that was great from the novel, but managing to sell it very successfully to a modern audience with all their expectations of an action-thriller met (much like the Bourne trilogy had done, proving an action film could also be a great thriller).
Sure, there's elements i'm sad they dropped, such as the extent and specifics of Fleming's the truly gruelling torture scene; the explosion which Bond miraculously escaped unscathed thanks to a lucky palm tree; and as you rightly say, the paranoia of the final act of the novel.
The biggest let down was the throwaway fashion in which they chose to deliver the final line of the book, "The bitch is dead", as though afraid of alienating the audience. After all, that alienation, to a certain extent was doubtless Fleming's intention - to state clearly and bluntly how much Bond had changed by the story's end - how dangerous and focused he'd now become - the moral question of cowboy's and indians left behind with Vesper.
Now, as McCartney said 'If you've got a job to do you gotta do it well', and Bond's job is now vengeance on SMERSH. Fleming new just how much that would make readers yearn for the next book.
In the movie the essence of this was only partially rescued by the cold blooded take down of Mr White in the epilogue.
But despite all this, the CR movie is easily the best adaptation of the series and if you don't think it's a good adaptation then what does that say about the rest of them?
I think the first thing that I'd say in response is that, when it comes to the other "adaptation" of Fleming's novels (and by that, I mean anything that's not DN, FRWL, GF, TB, OHMSS, FYEO, LTK, and CR), I don't really even consider them "adaptations", as they aren't even the slightest bit concerned with trying to actually adapt anything from the novels, so that kind of limits the pool of films from the outset. If you were to ask me what I thought of those films as adaptations of Fleming's work, then I'd say they're absolute crap, because that's what they are strictly as adaptations. As films on their own, they're of varying degrees (some are great, some are pretty bad), but strictly as adaptations of Fleming's work, they're not particularly good.
When it comes to Casino Royale, I'm not as impressed with it as an adaptation because it's easy to see where it could have been made both better as a film and as an adaptation while still not alienating the audience. It's clear, from the parkour, Miami, and sinking house sequences that EON wanted to imbue the film with certain elements that made the Brosnan films financially successful. These are scenes that really just aren't needed, especially when the best action sequences of the film are the smaller, lower-key ones such as the pre-titles and the stairwell fight.
The decision to base the film around the threat of terrorism, which already forces the film to drift towards standard action fare of the time, is misguided when they could have truly updated Fleming's novel by basing Le Chiffre's plot around trafficking. Taken proved, albeit after Casino Royale, that a film that revolves around human trafficking can be successful and not turn off its audience. If EON had put the same kind of bravery into developing the script for the film as they did in hiring a blonde actor to play James Bond, they could have come up with something that would have been fresh and original, both for the franchise as well as for the genre as a whole (as they would have beaten Taken to the punch) and allowed Casino Royale to both remain more faithful to the novel as well as not have to have the story launch from the already stale plot device of setting it against the global war on terror.
While I would say it's true that they did adapt chunks of the novel for the screen, they missed very important aspects of it as well. In terms of what they got right, it mostly resides in the fact that they included the three major components of the novel: the card game, the torture sequence, and the final line. The problem is, they watered each of those down as well. The novel's final line is simply a throwaway here, which is just annoying to say the least. The card game is poorly put together (nobody can keep track of how much money is actually at stake, they only show us hands that are of extreme importance to the plot, and the card combinations that are held by the players, especially in the final hand, are so ridiculously improbable that it's almost funny to watch them continually turn over the cards and one-up each other as they go around the table. Then there's the torture sequence which, while solid, doesn't even begin to touch that of the novel.
But the biggest problem for me with Casino Royale, is the fact that they basically ignore the final third of the novel. It would have been some of the most compelling stuff of the entire cinematic series had they shown Vesper breaking down on film as paranoia overtook her and ultimately drove her to her death. Instead, that's replaced with a house sinking into the canals of Venice. Some excellent acting opportunities for both Craig and Green, as well as the opportunity for some truly great, tension filled moments as well as some romantic moments as well, are discarded in favor of blowing more things up. It's a disappointment to say the least.