The Cyclotricity Stealth is for the adrenaline junkies among you.
It's a mountain bike at its heart, complete with 26-inch wheels and springy front suspension that easily absorbs stones on rough off-road surfaces. It looks every bit as aggressive as you'd want a serious off-road mountain bike to look. Made in Britain, it costs £1,295 from the company's website, which roughly converts to around $1,720 or AU$2,260. Cyclotricity ships around the world.
In the rear wheel is the electric motor, which provides a massive 1,000 watts of power. That's enough to propel you to 30 mph (48 kph) which, I can assure you, is an exhilarating speed when you're belting down gravel trails.
The motor can provide assistance to your pedalling, but there's a throttle too, which you can push down to ride the e-bike on the motor's power alone. You can use it if you're feeling lazy, but I found it immense fun to tear around hills purely powered by the throttle -- it turns mountain biking into something approaching motorcross. The Stealth is comfortable to ride on- or off-road, and even without motor assistance it's not difficult to get up to speed.