I'm kind of in the same boat, mid-life with grown kids so I can get pretty much anything I want (within reason of course) but don't want anything that screams "mid-life crisis!" I did the sports car thing in my early 20's, but now I'm looking for something fun to drive, but refined and comfortable as well. Here are some cars that I'm considering:
Buick Regal turbo- very nice car overall, great interior with good handling and decent performance/gas mileage. Test drove a 2012 and a 2013 model a while back and almost bought one that day.
Acura TSX- Good, high quality interior (not as stylish as the Regal though) good performance/gas mileage. The only thing holding me back is a feeling the handling isn't quite what it should be considering the suspension is on the stiff side. Overall, good car with nice lux features.
Ford Fusion Titanium- Best looking of the bunch (my opinion) and surprisingly good performance/gas mileage combo with the 2.0T ecoboost. It handles well andthe interior is a nice place to be no doubt, and filled with tech features...but looks a little spartan compared to the Regal and TSX.
I'd have to say at this time I am leaning towards the Regal. Never thought in a million years I would want anything with a Buick badge, but keep in mind it's actually an Opel Insignia which won European car of the year back when it was released. Between the 3 I've chosen it's second only to the Fusion in looks/outright acceleration, most stylish interior (which is super quiet), composed handling and smooth ride. The gas mileage isn't as good as the other two, but I now have a8 minute commute to work so that isn't a factor