There are so many fantastic movies out there that it really is hard to nominate a favourite.
Instead I'll go with a movie which I cannot help watching whenever it's on TV
Remember The Titans is brilliant. I remember the first time I watched it, my then Girlfriend was working in a video store and she was able to get me a great deal on a bunch of ex-rental titles and this was among them.
I won't spoil the plot, but it's a High School football story with a strong social message and is based on a true story.
The cast is pretty impressive too. Denzel Washington plays the lead role, and there's a raft of early appearances from some well known names like Ryan Gosling, Don Faison, Ryan Hurst, Kate Bosworth, Hayden Panettiere to name a few.