I personally use GMail, I had a hotmail account before my Gmail account and changed to be honest because it got hacked so I thought a sensible idea would be to have an email address that is separate to my live ID however still the same address to get away from the confusion. I feel that there is no really need to change as it does what I want it to do along with giving me access to great features like Google Docs so if I need to note something down or put something together quickly I have that to fall back on.
So that is why I am using it, because although Google is surrounded by privacy concerns you have to turn it around and unless you have a server sat in your home no mail service is actually going to be risk free from privacy issues.
