Effective classrom and worthwhile and valuable experience

3.  What do you think an effective classroom looks like? What makes a classroom experience worthwhile and valuable?
 An effective classrom should be a place where you're not afraid to express you're opinion, where you respect everyone, but you're sincere and have a critic perspective, because you believe that not everyting is perfect and that the evolution never stops. I'm not saying that we should critiquize everyting or that we should make destructive statments, I'm just saying that helping others with our sincere opinion is the path to a richer learning.
Let's be corny, I believe that our personality should be reflected in our conversations and wirting and we shouldn't hide what we're just because we want to have a good grade. Of course, that when we're in a environment where a teacher don't stand is an oppressor, of course we have to play the game and just learn to be fake.
For me , the more significant learnings were the ones made trough investigation , visit studies , learnings that prepared us to the daily life. For example, once I gave a class where I talked about vulcanoes because in my islands there is a lot of them, so all the students wanted to talk about the ones they knew,etc.
Finaly, I think that when the teachers give liberty with responsibility we can be the best that we want to be and love what we do.