I use hotmail as my secondary webbased email account. I much prefer yahoo as you get more storage and its better layed out and easier to use.
Hotmail only gives you 2mb storage, for me because I use very active newsgroups this can get full in a day or two...reciving 100+ emails per day.
Another annoying problem with it is the ammount of spammail I recieve. I dont use this address to sign up to anything, leave in guestbooks/ profiles etc, so where is my address found? The newsgroups I use are ones which hide your email so why am I getting all this email? Probably because my email address is something that is obvios a person will have chosen (hope that last sentence made sense).
I also think the layout is really boring, dull, and trying to be too professional. Yahoo is fun in my opinion and a much better alternative. The site is alo really slow but this may just be my computer.
The one good thing about hotmail is the MSN messenger which accompanys it, its much easier to use than yahoo messenger and I use this all the time to talk to my friends.