I like Joseph Campbell. I like studies of mythology and patterns in stories, and I like the Hero's Journey. I've used it to help me plot more than once.
Of course, there are elements to The Hero's Journey that don't fit into every story (What if you don't have Shapeshifters? What does Return With The Elixir mean, exactly?) and while on the one hand it can force you to think about your story in new ways, sometimes…sometimes you just want to get to the meat 'n' potatoes.
Like I've said before, for me plot is conflict, and the story is the resolution of those conflicts. I was going through old notes this weekend (trying to consolidate 10 years' worth of notebooks into a single computer program–you may laugh at my ambition, I certainly do) when I came across this very simple plot outline:
Who is the hero/heroine?
What does the hero want?
The door opens.
The hero takes control.
A monkey wrench is thrown.
Things fall apart.
The hero hits bottom.
The hero risks all.
What does the hero get?
It's like a stripped-down version of the Hero's Journey, focusing on your protagonists and his/her goals.
