Wow, I'm loving this thread, and I feel it deserves a bit of a bump.
I'm only a sophomore in high school, so my acting classes are very much a buffet of acting styles (and a rather laid-back approach at that, unfortunately). So, at this point, I can't really attest to which school of thought I side more with. But I can tell you as I feel out the different styles and exercises and experiment with different ways of approaching a character, I'm beginning to know what I like and don't like.
I hate the intellectual, written aspects of preparation that I'm forced to do for school. Marking beats, writing character histories, writing subtext, I despise it. It seems so extraneous to me to go beyond the text, I have everything I need right there. At the end of a show, my script is destroyed with questions and answers written in every margin, but if something isn't brought up in the play, I don't think its necessary for me to even think about it, because if I make it important enough to my character for the audience to become aware of it, I'm likely to just confuse them. If its just a tiny subtlety that no one but me could possibly pick up on, than all I've done is waste time.
One of the things I love about what Mamet had to say in True or False was the idea of never "Um"ing or adding words in order to save time and find a safe moment. I love seeing an actor take an emotion and run with it, even if its scary or confusing. But I can't agree that going to school for acting is useless, as those startling and fantastic moments just won't come to you every night, and you need something to do in case it doesn't happen.
I also love Viewpoints. I am most intrigued by an actor that is physically in their body and is aware. I am so annoyed by an actor that isn't both physically and mentally present 100% of the time. And I think constantly having that awareness of what's going on in yourself, as well as your relationship to others is half the battle for an actor.
But, I have the feeling that I'm really a Meisner girl, as my favorite exercises that we've done in my class have been, to my knowledge, Meisner exercises. Lots of repetition. Personally, I am triggered most by what I'm given, and I try to allow the other character's lines to guide what I'm doing more than my own.
And I also try to allow what's affecting me at any moment to work itself into the scene, and not deny any emotion, even if I feel it may betray what the character "should" be feeling. No matter what it is, I try to grab that feeling by the balls, and run with it.
My apologies if any of this is obvious or extremely basic, I'm in the very early stages of figuring out my technique.
Theatre is a safe place to do the unsafe things that need to be done.
-John Patrick Shanley