"Best" is something illusive.

It will help to narrow it down a bit if we knew...
-how long is the commute (and is it all weather)
-what sort of sport are you after (responsive and racy, stable and suitable for long rides, a tourer, etc)
-do you view yourself as a preservationist, or someone who wants a modernized bike with vintage/classic style
-will you be using it lightly, or will it get tossed in a bike rack at work?