In nine years and nine months of commuting, and as a participant in the Commuting Forum, what I've found works best is a bike you love, that makes you want to use it instead of the car, then rewards you for doing so.

No one can tell you what that bike will be for you. But the place to start is looking at what you already like to ride. If you have a tri bike in the work stand, then I wouldn't suggest an MTB, for instance.

For commuting, as in touring, it depends on you're going fully loaded or not. A credit-card tourer doesn't need the things a fully-loaded one does. No point in looking at racks and fenders for your commuter if you intend to drive your clothes and week's worth of lunches to work on Mondays.

Personally, I love roadies. But I also don't own a car, so I need something to tote my stuff too.

The solution I've settled on is a bike that's the bastard child of a cross bike and light tourer for hauling stuff to work on Mondays and bringing home the laundry on Thursdays (four-day work-week). Then on Tuesdays and Wednesdays I can ride any bike I like.

Eight miles each way is a nice little commute. Long enough to work out the morning kinks and work out the stress on the way home, but not so long that you can't ride just about anything.

So rather than try to take someone else's idea (even my own) of what constitutes a "commuter" bike, then making it fit you and your nature, think more about yourself and what would give you a fun ride twice a day, then fit that to commuting.

That said, looking at your stable, something from the current crop of "gravel grinder" bikes might be just the ticket--28s under fenders, maybe rack eyelets. Gets the job done, rewards taking the long way home, and not a pig by any means.