Peter Sellers stars as Harold Fine, a self-described square--a 35-year-old Los Angeles Lawyer who is not looking forward to middle age and his upcoming wedding. His life changes, however, when he falls in love with Nancy, a free-spirited, innocent, and beautiful young hippie. After Harold and his family enjoy some of her "groovy" brownies, he decides to "drop out" with her and become a hippie too. But can he return to his old life when he discovers that the hippie lifestyle is just a little too independent and irresponsible for his tastes?

Paul Bratter, a conservative young lawyer, marries a vivacious young woman, Corrie. Their highly passionate relationship descends into comical discord in a five-flight New York City walk-up apartment.

Two desperate people have a wonderful romance, but their political views and convictions drive them apart.

Felix Ungar has just broken up with his wife. Despondent, he goes to kill himself but is saved by his friend Oscar Madison. With nowhere else to go, Felix is urged by Oscar to move in with him, at least for a while. The only problem is that Felix is neat, tidy, and neurotic, whereas Oscar is slovenly and casual.

Super-spy Flint takes on a cabal of women plotting to rule the world.