I LOVE Holy Grail. I think it would be in my top 5 films of all time.
I love both of those, and they are great. The one film that made me laugh more than any other though is Start the Revolution Without Me - Donald Sutherland and Gene Wilder playing two sets of identical twins in the French Revolution. The whole cast is great, I end up snorting with laughter, it's just so ridiculous and fab.