My point of view will be different from others' because I read some of Fleming's books before seeing the movies. From that, Craig has become my favourite Bond because he comes closest to the novel. Connery was my favourite film Bond up until Casino Royale because he could do both suave and menacing, but Craig flips between the two modes more readily and keeps you on your toes more.
I'd like to cast a sympathy vote for Lazenby, whose greatest sin was not being Connery and who could've made a better Bond than Brosnan or Moore if he'd been given a chance. I do like some of Moore's efforts, especially when he nails the "killer" aspect, but he seemed to be too immortal when in the role. Dalton would've been fine except for the crap scripts they kept giving him.
-- Steve
Edited to add: Forgot to comment on Brosnan. I think he's a great actor, but I never saw him nail the "dangerous" aspect of Bond as well as Connery, Craig, or Moore (at Moore's peak) and so I rate him relatively low as a Bond. I never once felt that Brosnan's Bond would be just as happy to kill you as charm you... though I did greatly enjoy his performance (and commentary track on the DVD!) in Die Another Day.