Watching it again, I realised that my brother Mica is quite right about something: "On Her Majesty's Secret Service" is the best James Bond movie. The major reason is simple enough - Diana Rigg. In classic Avengers style, she is gorgeous and obviously intelligent. An actual equal for Bond, as underlined by his willingness to marry her. Unlike later films, where Bond seems extremely seedy, lucky, and gadget laden, in this film he is actually a reasonable hero. Blofeld, at the same time, is quite a good villain.
There are flaws, of course. The sped-up fight scenes, which look ridiculous, are one. Sometimes, the creative editing looks stupid. At other times, like when Bond sees Tracy being dragged away in the MI6 window in London, it is quite clever. Also clever is the whole resignation sequence, which smacks of an unusual kind of dramatic tension in a Bond film.
The high point, of course, is simply Diana Rigg being so, so sexy. I love how she is actually competent, unlike almost everyone in the Bond films. She dispatches underlings with a skill nearly matching that of 007 and manages to look smashingly good while she does it. This is a film that doesn't have to rely on special effects and gadgetry to impress. The scene where his wife dies manages to evoke a genuine sense of tragedy: an emotion of a higher order than you expect in a Bond movie... "Now we have all the time in the world."