Ooh, I like this thread.
This one, for obvious reasons.
[video=youtube;SEllHMWkXEU]https://www.youtube.com/watch?v=SEllHMWkXEU[/video]
This one, because during one scene someone's waving a fully serrated Spyderco Police.
[video=youtube;z5rRZdiu1UE]https://www.youtube.com/watch?v=z5rRZdiu1UE[/video]
This one has a lot of shiv action and Danny Trejo, I think that should count as well. (Video is quite gory, mind you. It is Slayer after all.)
[video=youtube;yjb0j9l1sz4]https://www.youtube.com/watch?v=yjb0j9l1sz4[/video]