I have the four of them. For me, the better one is "Stripped" but it doesn't mean I don't like the last three . In second place, I prefer "Missundaztood". Then, it'll be "Breakaway" and in the last place there's "Let Go". The four of them are four of the best pop albums of last decade.
I actually didn't listen to Let Go and Stripped in full cos singles didn't really intrigue me. I listened to Breakaway, however, besides a few high points, I found it to be average overall. (Behind These Hazel Eyes and Since U Been Gone are pop milestones, I love Addicted)
Miss >hugegap> Breakaway >gap> Let Go = Stripped (Complicated and The Voice Within were my jams at a point )