What's the Best Tank Related Movie?

I am a U-boat fan so I enjoy SHIII very much, and most folks in that forum would state that Das Boot was the greastest U-boat film made in histoy. What if any are the best tank related films? I think I remember seeing a movie about a father who stole a US Army tank from a base and used it against a local police department that was corrupt or something, but I didn't care for it much. It seemed too fake and the stupid cops were shooting at the tank with pistols . Is there any movies that are about tanks or a tank crew that is based on a real life situation? Something like the 'Memphis Belle' movie that was about a B-17 flying fortress crew during WWII. It had some comical moments to it, but was based on a true story about the actual crew. Anyways, post what you know or post a link to such movies if there are any.