If the battle for the loyalty of motorcycling's next generation is happening anywhere, it's in the lightweight streetbike class. The great offerings under 500cc fight not only for new riders but also for enthusiasts with decades of experience. The fast and fun Yamaha YZF-R3 won our recent light sportbike shootout for good reason, but when we sat down to hash out the best all-rounder in the class, we kept coming back to the standard-style 390 Duke. Its 373cc single offers lots of tractable torque and a 40-horse peak in a practical, affordable package. Pure flexible fun for all kinds of riders.