I'm a long-time supporter of Yahoo Mail. I use it everyday, although I still maintain active Live Hotmail and Gmail accounts.
And recently, Yahoo Mail just got even better, with official support for the Safari 3 web browser on Mac/PC. And somehow or other, the big long rectangular ad on the right of the mail page disappeared, meaning more space to view your emails and no more annoying ads.
The good just got better, and for people like me who access Yahoo mail on Safari daily, this is simply great.