After using Hotmail for well over a year now I have to say that Im very happy with the serverce. The main reason that I use my Hotmail account is because of the speed, Hotmail is the fastest free, web-based e-mail that I have ever used! I also like it because it can easly be set-up to be used in an e-mail client as well (there is a guide in the options menu).
When you log-in to your account (which can be from any computer) you are presented with a nice, easy-to-use interface. When you log-in your are taken to your inbox right away and any new messages you have will be highlighted so you can easyly see your new ones.
There is also a handy address book which can be used to store your contacts and if they use MSN messenger it will display their status as well, a nice feature.
There are other cool options as well such as being able to block senders e-mail address (to stop spammers e-mails from getting to your inbow). You can also choose how many messages to display per page and you can create a signature (your name or something which will be displayed on every e-mail you send)
The only thing I have againest Hotmail is the inbox limit which is only about 2MB. This can be used quite quickly if you recieve pictures etc in your e-mail.
Overall I think Hotmail is great. Its fast and has lots of features, such as a spell check. The only thing thats bad about it is the low space given to you.