gMail beats Hotmail or mail.com or Yahoo! Mail hands down. Why?
Because it's a cleaner interface (no ads blocking valuable screen-space).
It's faster.
The SPAM features are awesome.
The space they give you (2.5 GB as of today) is way more than you'll ever find for free anywhere.
There are no "folders" but rather "Labels" so all your mail is in your "All Mail" folder with labels. Sorting through emails is so much easier without looking in folders, you just look in "All Mail", and if you need a specific topic: select the label.
You can search inside your emails easier.
It's tied directly into Google so you get your own personalized homepage too.
GoogleTalk is tied into gMail and I'm sure there are extensions/plug-ins for gMail for MSN, Yahoo!, AIM, Trillian, gAIM, Miranda or whatever chat program you use.
So, gMail is better. I've used all the email services you can probably think of. I'm truly enthused with gMail and love it. Never hurts to try, you can always delete your account later (yes, you can delete your email account).
Consider your invite in the mail....