I was going to ask everyone about this one. I love it, it's so funny, Bill Murray is a...I don't know what you'd call it, his wife left him and he is a mess, like distant cousin of Adrian Monk kind of mess I think...and then he turns his psychiatrist's life into a nightmare by following after he and his family and he won't leave them alone, and the family loves him, but the father/shrink HATES him. And to know that in real life Richard Dreyfuss and Bill Murray did NOT get along, that just makes it all the funnier to watch.
The one thing I think most people will remember from this movie, of course: "I'M SAILING!"