Nah, Life of Brian is by far the best. It has the best plot, the best jokes, and the best conclusion. I still think Holy Grail's ending let it down badly, it just seemed like they ran out of ideas so decided to do something completely irrelevant just for a laugh, but as an end to a film it really didn't work for me.
I agree, Meaning of Life had some highlights ("Every sperm is sacred" springs to mind) but overall, it was a bit weak.
But although I saw Holy Grail first and probably found it funnier, I think Brian is the better film. A bolder target of satire, more interesting scenarios, and more insightful comments -- I especially like the social commentary of the "what did the Romans ever do for us?" speech. Holy Grail probably had more laughs per minute, but Brian was truly inspired in concept and execution I think.
I've just got back from performing our third mointy python sketches (our firs and secound bein llife of brien and holy grail) we did scene's from the meaning of life - the docter scene (at the begining) , the army scene and the grim reaper scene (at the end) and two from ANFSCD - Camp Camp and the fish slapping scene ( with real fish) *stinks of fish* .