Milk is always organic for us too. I can taste such a difference between organic and non organic milk. We do organic yogurt most of the time too b/c I try to stay away from dyes but the other yogurts are getting better about not adding them. I would love to do meat organic but just can't afford it right now.
I buy organic for the dirty dozen list of fruits and vegetables and anything my son eats in high volume (milk, certain snacks, yogurt). I'd like to do meat but it's just too expensive. I'l also buy organic when its the same price or cheaper than the regular for all food categories. I noticed that happens often for pasta and canned beans.