Depends on what size you want. Harley's are nice but can run a bit rough. Ive heard great things about the Honda Shadow - although im more of a sport bike girl myself.
I didnt start ridin till I was late 40's, bought a 99 Honda Shadow 1100cc Aero, bike was in great shape, still is and reasonably priced. Great for one up or two up riding, Horse Power fits my biking experience, I havent out grown it yet. Enjoy when you take the plunge.