I personally use "I personally" occasionally.
I think it stresses the fact that the statement you are about to make is more deeply rooted in your personal believes and behaviours or even a major part of your personality and not only a random thought that just crossed your mind.
Also it implies the understanding that you are not talking about something you consider to be a universal truth, but just something related to your person, thereby recognizing that other people might have their own very different personal views.