"The Shawshank Redemption" is probably my favorite movie based on a Stephen King novel. It is flawlessly acted and a truly riveting movie. It has so many memorable scenes, but I would guess the wrongly-convicted Andy Dufresne's escape from Shawshank Prison is probably my favorite in the film.
This clip is just over nine minutes, and goes from when Andy is first discovered missing up until Andy tasting freedom for the first time in 19 years.
This is YouTube clip number 27. Enjoy.