Really? I've never seen a better webmail interface than Gmail's. Can you justify your claim by providing some of "it's" qualities that are so laughable?
Edit: And as I posted to my Tumblr (http://ajh.us/GmUI) just 5 days ago:
> Today I opened a Gmail window. At the top of the screen, I saw a yellow message beginning, “Hey, this is important! …” I never finished reading it because I had clicked something else (a message) and the supposedly important message disappeared, never to be seen again.
> So the Gmail team either
> 1. Lied about the importance of the message, or
> 2. Totally failed to make me actually read it.
> Not so impressive UI design.