OK, maybe this will be lame, since this is just me reminiscing about the past, but I present you with my two favorite 1970's movie comedies (in order in which they came out):
#1 Blazing Sadles
I have never seen a movie in my entire life in which the audience laughed louder and harder than at this movie. I 'm not sure if this is the movie I laughed the most at, but it might well be. I saw this on the base (Maxwell AFB in Montgomery Alabama) with my high school girl friend. We saw the late show, and the only seats still open were in the very front row, on the very side, that's all that was left. The audience was 50/50 black/white, and they (and I) loved every minute of it. Roared like lions - you'll never forget a movie when you see like this.
If I was a smarter, more profound person, I would explain how this was a high point in American race relations, but I lack the requisite skills; I hope someone else can fill in the gap. Honestly, I don't think this movie gets made today.
#2 Monty Python and the Holy Grail
You couldn't have possibly picked a different movie going experience if you tried. I mean really, really, tried. I saw this when it came out, I was on summer break, living with my parents, and down the street (it's a small world after all, if you're all in the military rotating in bases around the world) from my best friends from England (Catholic family; 12 kids, but I only knew the 9 youngest).
I was a huge Python fan, and me and 6 of my friends decided we had to see this movie. Only issue, the nearest place it was showing was near Silver Spring MD, so we had to take a 1 1/2 hour bus ride from Fairfax VA to see the movie. We were about half of the whole audience (matinee) but we loved it, and supplied at least enough laughter for the immediate environs.
An odd result of this adventure is that on the bus ride home, we told each other all the jokes from that movie over and over again, that by the time we had got home, we could basically recite the movie by heart. Even to this day, that sticks with me. Anyway, happy memories from the past.