Best gunfight: I'm wanting to say near the end of The Magnificent Seven for the pathos, but I'm sure that others will disagree on this point (replacing as their choice, something with entirely too much CG).
(Reposted) Most inspiring movie for roleplaying: The Adventures of Buckaroo Banzai Across the 8th Dimension. With the impossible made mundane, a band of talented misfits, and the world chanting their name, the Hong Kong Cavaliers are the ultimate pc troupe. In a sense, all player-characters are mere shadows of Dr. Bonzai. The movie has provided priceless inspiration, as a GM, player, and game designer. And the closing credits scene will have you whistling/humming the song for weeks.
Scariest horror film: Spiceworld, hands-down.