Best optical mouse?

What’s the best optical mouse? (For Mac OS X, of course.)

I’ve been using the standard Apple optical mouse—and it’s great—except I also want a two-button mouse (at least two buttons) and a scroll wheel.

I don’t care if the mouse itself is wireless. The cord doesn’t get in my way. It’s just important that it be optical—I can’t go back to mechanical mice.

What do you recommend?