1- Connery. The first and best.
2- Craig. Fantastic!
3- Brosnan. Gets a nice mixture of Moore-ish charm and Connery-ish deadliness when necessary
4- Moore. I like him a lot, but he's basically still playing Simon Templar. Which is no bad thing, but that's why those three are above him in the James Bond stakes
5- Dalton. Could have been good, and shows flashes of proper Bond, but seems uncomfortable in the role rather than playing a Bond who's uncomfortable with his lot. As a result he seems to waver between playing it like it's vital Shakespearean art, and being embarrassed to be in something so populist. All the same, it's his voice I hear in my head when I read the books.
6- Lazenby. Actually underrated- he looks most like the character, but somebody has to come last.
I should point out that these ranks are merely relative to each other. As a whole, I love 'em all