Show me a mid size sedan that is stylish? In the last 20 years...
1st gen Mazda 6. 2004 - 2008 version. Of course, the hatch and wagon look even better, but the sedan still looks great today- and better than the (admittedly stylish) current Mazda6 IMO.
2004 - 2008 Acura TL. Looked great then, still looks great. That era's TSX was also really nice, but I prefer the TL by a hair.