All three "Terminator" movies feature shotguns very prominently, most famously Arnie's one-handed use of a Winchester 1887 (lever action) in T2 (riding a motorcycle, etc.).
The "Mummy" movies have some good old-school shotgunning, including the 1887.
"No Country for Old Men" has some good scenes. Many people say the suppressed shotgun is not realistic though.
"L.A. Confidential" has a pretty intense shotgun scene.
"Aliens" reminds us why shotguns can come in handy when investigating in strange locals.
"Army of Darkness" is one of the all time classics.
Tim Sizemore in "Heat", a good guy to back you up.
The "Mad Max" movies, "Dawn of the Dead" remake, the "Miami Vice" movie, there are tons. Are you looking for a particular model of shotgun in a film Terry?