Kawasaki Ninja 250The Kawasaki Ninja line is one of the most famous bikes from the manufacturer, and it's for good reason. The Ninja 250 was considered to be the quintessential starter bike for many years, and it's also one of the most reliable. Kawasaki has since retired this specific Ninja, but there are many riders today who say this is the motorcycle that introduced them to the world.It's easy to gauge its reliability just by how long it has remained on the market. The Ninja 250 line dates back to the 1980s, and the third generation of it lasted from 1988 to 2007. Throughout its production, changes were made here and there, but it remained largely the same bike through the decades. While the third-gen isn't produced anymore, you can find a used one on the market for a few thousand dollars if you're interested in a piece of history that's endured through the turn of the century.