I use GMX which to me is the best of the free services. Gmail is bloated and has too many features that I never use. Yahoo just has a terrible interface, in my opinion, and Hotmail I never have liked much. I don't keep mail after I've read it (with very few exceptions), I don't need any sorting features, and I turn off all provided spam filters. I let everything come through in Outlook Express and use the free version of SpamFighter to sort it out. That way I can see what has to be adjusted without having to go to a website to see what I may have missed that was classified by the provider as spam. I never get more than 5 or 6 spam mails a day and SpamFighter puts them in it's own folder where they are easily deleted. Another thing I don't like about Gmail is that the mail does not get deleted from their server after Outlook Express retrieves it even though it is set up in OE to do so. The GMX mail is cleanly removed automatically but I have to go to the Gmail site periodically to clean things out. I greatly prefer the interface of Outlook Express (or Windows Mail) to read my mail in. The web based interfaces are, without exception, terrible.
Update--- On going to the Gmail site, I discovered that you can't turn off their spam filtering. How stupid is that? I have had to make a custom filter to stop mail being sent to the spam folder. I just told it to ignore anything that has the @ symbol in the To field. That's basically everything so now it will all go to my inbox and be dealt with by Outlook Express and SpamFighter. I did however find out how to have mail in the inbox deleted after being retrieved by Outlook Express. It's buried in the myriad of mostly useless options. Gmail sucks in my honest opinion.