Well it's obvious why they do that for the movies-- to introduce fresh tail and all, but movie-Bond is all I know.
It does make sense Royale's case, but Moonraker was a very exciting book and would make a great movie. Instead they tried to cash in on the St*r WarzzZZ craze and totally butchered it. And then you have films like "Live and Let Die" and "From Russia with Love." which are much slower, but are pretty faithful to the novels.
I have to know: who's your favorite Bond?
Brosnan. But there is a lot of bias behind that, as Goldeneye was the first Bond flick I saw in the theater. Goldeneye is also my favorite Bond film. (A buddy of mine swears up and down that Moore is the best and the Moonraker is best film for the same reason.) But I really do think he looks the look based on the book description of Bond.
After Brosnan, it's Dalton, Connery, Lazenby, and then Moore. I'll have to wait and see on Daniel Craig, but I know he is the most Un-Bond in appearance since Moore.