AS far as browsers go, I think Opera innovates better than anyone. The speed dial interface you see in other browsers now was copied from them and poorly at that. Unified search & address bar appeared in Opera first (at least that's the first place I saw it). Custom search engines & shortcuts are awesome. And I rather like the mail client.

Don't get me wrong, it has its downsides. But it's much lighter weight on memory than Firefox and better on CPU than Chrome in my experience. And I don't get all the weird ass blitting issues I seem to have with Safari. I've also run into far fewer crashes. So, when it works on a site it's phenomenal to use. When it doesn't, it kinda sucks.