Life Of Brian for me too.
Just the most consistently funny movie I have ever seen, not a wasted line or duff gag anywhere.
Yes, you could argue that it's a typical Python collection of similarly themed, connected sketches, but they all work.
Everyone knows the routines...the sermon on the mount (SPEAK UP!)...the stoning (WELL YOU DID SAY JEHOVAH)...the Judean Peoples Front (WHAT HAVE THE ROMANS EVER DONE FOR US?)...the romans (I HAVE A VEWY GWEAT FWIEND IN WOME CALLED BIGGUS DICKUS)...the writing on the wall (CONJUGATE THE VERB TO GO)...the followers (HOW SHALL WE F**K OFF, O LORD)...the cruxificion (ALWAYS LOOK ON THE BRIGHT SIDE OF LIFE).
Sheer class.