IT'S A WONDERFUL LIFE is, and always will be, one of the best holiday movies. The strong message of being thankful and living life to the fullest never ceases to inspire. You're always rooting for George Banks to see how precious his life really is.
As the film opens, you hear a voice in the stars (supposedly God) speaking to another star named Clarence. He tells Clarence that he must go down to Earth to save George, who is about to take God's most precious gift (life). We then see the events of George's life played out, up to the point where Clarence, his charming guardian angel, must show him how great his life really is. And the only way to do this...show him what life would be like if he never were born.
The overall theme of suicide is tense but not scary. There is no violence or language. Sex is very minor, with no sex, but when George and his soon-to-be wife are playing, she runs and her robe gets snagged in a bush. She then hides in the bush (we hear her voice) and is presumably nude (but we don't see anything at all).
It's a great movie. Watch it if you can.