This Giant electric-assist bike is turning out to be a favorite of mine. It's a lot of fun to ride, and it's a useful tool. Today, it was so windy that I probably wouldn't have ridden any other bike. If I had, I would have ridden no more than 10 mph. With the Giant, I averaged a good 16 mph, without too much effort.
Get your e-bike at Electric Bikes Northwest+California; they stock the best brands and give excellent service: http://www.electricvehiclesnw.com/ (I am not affiliated with this shop.)