I think hotmail is probably the best and biggest free email service provider because mircosoft is an internationally known company and because of all the years of experienced they hold.
the features i feel best for hotmail are how it is so user friendly the layout is set out very simply so things can be used as simply and effectively as possible.
if i could change one thing i would probably change their support system as you can wait anything up 2 two weeks for help with something. something such as a live support system would be very useful.