head would say Honda NC750 or Yam MT07 or 09 - rave reviews, cheap and plenty of mpg, heart would say something different and fun on your short runs to work, so maybe a KTM 690 or an Aprilia Shiver/Tuono or a Jap mid engine Versys or V Strom?
I believe you fit the bike to your stage of life, I don't have a full luggage GS anymore for the one long trip I did a year, I use the Aprilia mostly for the short runs I do and boy its so much more enjoyable, maybe a year or two down the road it will change again? Or maybe I am just a typical restless biker!!