For my money, the best Mel Brooks' movies are the ones that he doesn't appear or barely appears in, like THE TWELVE CHAIRS, YOUNG FRANKENSTEIN, and THE PRODUCERS. This film is one of the exceptions. Also, for my money, the best Mel Brooks' movies are those that are flat out parodies of film genres--like BLAZING SADDLES and SPACEBALLS. This film is the highest achievement of his parodic form.
HIGH ANXIETY is Alfred Hitchcock on goofballs. The references are wide-ranging: "Psycho", "The Birds", "Vertigo" (the main parody plot), "The Man Who Knew Too Much", "Notorious", etc. The result is out and out Brooks' mania, and, of course, a certain reverence to Hitchcock. My only negative comment isn't specific to this film but it does apply: most parodies run out of gas during the course of a feature length film. Once the novelty wears off, the film kind of lags. That's why the best film parodies are usually skits on variety or comedy television shows. Probably the only exception to my theory would be 1980's "Airplane". (See my review of that for a further explanation.) Still, HIGH ANXIETY has enough manic energy to sustain it for the most part. It's a clever film and extremely entertaining.