"The Producers" is being released on DVD tomorrow.
Those early Woody Allen movies like "Sleeper" and "Bananas" are also pretty funny.
Some pretty reliable classic comedies are "It Happened One Night", "His Girl Friday", "Some Like it Hot", and "Sullivan's Travels".
For more recent stuff, I liked "Bowfinger" and "Meet the Parents". The latter might be either an especially appropriate or especially inappropriate choice depending on your relationship with your father-in-law.

Oh, and in the interest of full disclosure I will admit that I laughed my head off at "Tommy Boy" on more than one occasion.
Regards,