Have a 2008 Triumph Bonneville, 1981 Yamaha Seca 550 Cafe Racer and a 1973 Honda CB500 Four. The Mrs. rides the 500 Four predominantly. Love my Triumph. Big enough to pass at 80+ but not too bulky and takes corners pretty nicely.
I think Seca and Seca II are excellent beginner bikes. Super reliable, not too heavy but have good acceleration and handle nicely. Look them up on Craigslist in your area if you are shopping for a first bike.
For beginners who want a new bike, I think the new Moto Guzzi V7 Classic is a kick ass looking bike that is a good size for a new rider. Review Here