KLR is the perfect bike for this. Dead easy for maintenance, gas and oil is all it needs for the most part. Slap on some chain lube once in a while and worry about little else.
Drop it, no problem. Not much to break, ugly anyway is stuff does break and so many parts are out there it is stupid cheap to fix.
Get 45-55 MPG, 'nuff said.
Tons of waterproof luggage options.
Reliable as a mule.
Tires can last up to 10,000 miles or more and only cost $100 a set depending on which you pick. Chnage them yourself in under an hour with a set of spoons.
Forgiving and easy to ride. Enough power to get where you need to go, not so much to get you into trouble.
I use mine almost everyday for commuting 26 miles one way, rain or shine, cold or hot. I do not ride in the snow or after we have had rain/snow melt and a freeze for fear of black ice.
You can find a KLR in every possible price range in every possible configuration, most are nicely set up for touring/commuting already.
There are many bikes out there that will do the job better than the KLR, but few if any that can do it as well and do as many things at the rock bottom TCO the KLR has.
2007 BMW R1200RT
2002 Honda XR400r