Each 'Bond' has bought their own charector to the role, but fundamentally they represent that particular generation for when the film was released.
Connery - Iconic. The original & still the best.
George Lazenby - So bad he only did one film & then they bought back Connery!
Moore - Slightly more laid back & comedic, I almost expected him to be smoking a Hamlet cigar in every scene.
Dalton - He will forever be associated with Peter Pan & Flash Gordon in my eyes, so not a good choice for playing Bond.
Brosnan - Ok, but not great. The ridiculousness of most of the stunts in his series of films probably served more to damage the Bond brand more than anything else.
Craig - Probably the best bond (behind Connery) as far as I'm concerned, but a direct comparison cant really be made as the new films have to serve a newer audience that demand more 'realistic' & gritty storylines & stunts (a'la Bourne Identity) etc.