The final scene of Rambo: First Blood is a classic bit of cinema. Unfortunately, all the good versions of the clip I could find on YouTube had Embedding disabled so I'll have to settle with a link:
I really like to see actors who are normally dismissed as action movie stars show off some real acting. It's easy to forget that Stallone can do more with his characters than jump out of a helicopter with guns blazing and such. Same deal with Bruce Willis of Die Hard fame. Again, YouTube is letting me down today; I couldn't find a clip of the scene but if you've seen Unbreakable  or have it lying around on DVD maybe you can check it out. I am referring to the scene in the kitchen/dining room when their son points a gun at Willis' character and both parents have to talk him down.