I actuly use both but i perfer hotmail on yahoo..may be all my family and friends are on hotmail. but yahoo is changing rapidly. and It is changing for good. I have noticed y ahoo messenger has become very slow. which i dun like about it.
in my opinion i prefer hotmail.com because it provided the easiest way to me to send email and received email.i think the hotmail.com population is more than yahoo.com. that is my opinion.good luck to you.
I have both accounts, but I prefer Yahoo! simply because it gives me font options. I do alot of reports and I have to email them out. I can't do the BOLD and different colours on Hotmail...but I can on Yahoo!