Helping people with computers... one answer at a time.
Free email accounts, when used properly, can be very useful. Google's GMail is the current best of breed, primarily because it can be "used properly".
The fact that I'm recommending a free email service at all will come as a shock to most of my long time readers. I've long ranted against using free email services as the sole repository for your important information. Most people read that as being "against free email", but it's really "against putting all your eggs in someone else's basket and only in someone else's basket".
Free email accounts have a place in your overall email strategy.
And one of the reasons I recommend GMail, Google's free email service is that it allows you to take control of your email in ways that the other services will not. In fact, I can see situations where GMail might be your primary email account.
Just never your only email account.
Forget all the other features you might think of when you look at GMail. There are exactly two that, in my mind, make GMail the free account to use:
It explicitly and clearly supports IMAP, POP3 and SMTP access, meaning that you can use GMail from any traditional desktop mail program. For example, I have Thunderbird configured to access my GMail account.
It explicitly and clearly allows you to automatically forward your GMail mail to any other email address you might want to.
The reason I consider those GMail's most important features is simple: data portability and the ability to back up.
Every day I get questions and requests from people using other free email services who've lost their email, lost the accounts, lost their contacts or more because of some problem with that other service. The other services make using something other than those services extremely difficult, or lock you into specific programs or ways of doing things. Thus, you're encouraged or even required to keep all your information within those services. If you lose that account, then all the information is gone, often irretrievably.
Not so with Google Mail. Use a POP3 client and you can take and backup your GMail email anywhere. Forward your Google Mail to any other email account, and you have instant and automatic backup of all your messages.
Google Mail doesn't try to lock you into its way of doing things. You can happily use GMail without ever visiting the website after you've set it up. Or you can. It's your choice.
You want more features? Fair enough:
Themes is the most recently released feature - you can change the look and feel of GMail to suit your taste, rather than be stuck with the old boring color scheme. I now have a nice pebble and rocks background when I log in to GMail.
Spam - or rather the lack there of. GMail appears to have one of the better spam filters out there. In fact, I know of people who have their normal non-Google email address automatically forwarded to GMail simply so that it gets spam filtered, and then have GMail auto forward what's left to another account where they actually access it - GMail is simply the spam filter in the middle.
Integration with other Google services such as the instant messaging client Google Talk, a new voice and video chat feature, Google Calendar and many more (be sure to check out the "Labs" tab in GMail's options).
Https access. For those of you on the road using open WiFi hotspots or other questionably secure connections, Google Mail's web interface can be instructed to operate only over an encrypted https connection for security.
Storage and lots of it. I know many of the other services are finally adding lots of storage as well, but as an example I'm currently showing over 7 gigabytes of available space for my saved email. That's a lot of space.
Google's GMail also appears to be one of the more reliable services as well, which I think also counts for a lot. To me, that means fewer lost accounts, fewer lost contacts and so on.
But I do have to reiterate that you should never use any free email account, even GMail, as the only place you keep important information. Free means exactly that - free. There is no customer service number to call, and support is primarily limited to on-line help information. For example, if you forget your password and the online recovery tools don't work for you, you may lose your account and everything in it. (I get sporadic reports from all the services of people who've been able to recover, but it seems to be a very, very small minority and not something you can count on in the least.)
But again, that's why Google's my service of choice - it's easy to set up a backup plan so that when or if you have a problem accessing your account, the amount of information you might lose can be very, very small.
GMail. Free email I can recommend.