I will have to disagree with the eminent SAF somewhat - I think in front of camera (and I’ll come to the lead actors in a moment), it’s hard to find someone for whom their Bond appearance was their best work. While Bardem was terrific in SF, he’s been the villain better elsewhere. Rigg, Lee (Christopher), Wright, Mikkelson, all great, but not their best.
Behind the camera a different story - Young, Hunt, Glenn, and Campbell, this is their best. Maibaum ditto. Barry - different discussion. His Bond work is up there with other more acclaimed scores (Out Of Africa etc). Deakins too - that he didn’t get an Oscar for SF, a travesty, but like Barry, the body of work so impressive, that for their Bond stuff to be in the conversation at all is noteworthy.
As for leads, it depends how you feel about them, but as SC discovered first, Bond defines you, not the other way around. SC has an Oscar, and some of his post-Bond 70s work is outstanding (The Offence, insert Meteor joke right here); frankly he’s brilliant in The Hill and The Molly Maguires.
Sir Rog, maybe, but carrying The Saint all those years…
TD - his role in The Lion In Winter brought him to EON’s attention; I’d offer that’s his screen apex.
Brozza - in Tailor and Matador, he surprised me. I’ll be generous, the Bond written for him restrained him.
DC - we’ll have to see. Bond is such a defining role, you have get some distance to let the light shine across your resume. DC is great in Layer Cake, Friends in the North, and Perdition.
Front of camera - no, not anyone’s best.
Behind? - For sure. Working on a Bond a career-maker for quite a few.