I'd look at mountain bikes, if I were you. They don't have to be ridden through impossible terrain, you know.
I think your best bet might be to go to your LBS, tell them what you told us, and take a few bikes for a spin around the parking lot. Don't be shocked if you fall in love with a bike you didn't think you'd even consider. Sometimes these things just happen.
Take a look at used bikes, too. There are deals out there. I got my William (the perfect bike for me) used for about half what I would have paid new.
Good luck in your search, and let us know what you decide. (Make, model, color, name, all of it.)
Give big space to the festive dog that make sport in the roadway. Avoid entanglement with your wheel spoke.
(Sign in Japan)
1978 Raleigh Gran Prix
2003 EZ Sport AX