Ill stick to the movies. I love the whole tv series stuff.
I Have to say HOLY GRAIL. I was about 12 when it came out. Didnt really understand most of it at the time, but my brother bought the "LP" of it and me an a buddy wore it out and had our favorite lines.
I to this day will say only the first Half of Life of Brian. I fall asleep on the second part.
I need to watch Meaning of life as an adult. Didnt understan most the humor as a kid. Grim reaper showing up at dinner and the puking fat guy are what stick out in my head.
As for other british stuff ,,, Are you being served, AB FAB, and As time goes bye with Madam Judy Dench

She rocks. I love her as "M"