There used to be a class of bikes called "sport tourers" that are perfect for this kind of riding. There's something to be said for owning a bike that has medium-length chainstays, a comfortable fit, enough tire clearance for 28c tires + fenders, and enough eyelets to easily mount a rear rack and fenders. Useful for commuting, light touring, and winter/wet riding.

It's not a marketing term used as much any more, but, to me, bikes like the Salsa Casserroll, Jamis Aurora Elite, and a number of cyclocross bikes would fit in this niche -- Soma Double Cross, Surly Crosscheck, Specialized Tricross, Kona Jake the Snake.

Bikes like the Gunnar Sport and Co-Motion Nor'wester also fit this fill if your budget can handle it. Rodriguez makes a model called the "Rainier" that is similar to this, too.

I find that over long distances in real-world conditions (especially chipseal roads or roads with dirty/uneven shoulders) it's still nice to have something with slightly bigger tires than a classic "road bike."