No such thing as an "Ideal commuter". The attributes that make a certain bike optimal for commuting depend largely on the individual commuter. Since a "typical" commuter will need to carry stuff, a CX, touring bike, or old school non-suspension MTB would make a good base. I'll be getting a track bike this week, and using it one day a week for my five mile, flat commute. Not something I would do every day.

YMMV