I would try to ride several bikes.....different brands, different styles, etc. and choose the bike you feel most comfortable with.
A drop bar road bike, to me, is the most comfortable but it's not suitable for anything more than smooth dirt roads if you want to go off the pavement with it. This is primarily because I run 700x23's on the road bike (very narrow tires). Some road bikes can handle wider tires and fenders.
It might be worth thinking long term such as "do I see myself wanting to carry stuff on the bike?". If yes, look for eyelets that will allow you to mount racks to the bike. These are great for carrying clothing if you commute, books, etc.