Nemo and Marlin almost die, in fact they almost kill each other, but by the end they find each other and are happy to be together. Nemo goes back to school and Marlin seems less afraid of life because his son has taught him how to weather the storm. As the end credits and bedtime started to roll, my son kept his eyes on the screen and said what Nemo says near the end of the movie: "Love you, dad."
He yelled the same thing to me from his bedroom that night, three times. I yelled it back, three times, even though we're trying hard not to yell at each other these days.