10. Ken Roczen
https://www.youtube.com/watch?v=1W3ab5zUnuc Ken Roczen is arguably the most successful rider in recent history to have made the trip across the Atlantic. The German rider was recognised as an incredible talent at a very young age, showcasing his potential by winning the 85cc youth World Championship. Roczen was an MX2 World Champion before he had turned 18, winning the title in 2011. He quickly decided to put his focus on conquering America, making the move and competing in the AMA Motocross series in 2012. He finished an impressive fourth in his first season, and took his first victory in the States at Unadilla at the end of the season. In 2013 Roczen truly made his mark by winning the 250cc West Region Supercross Title ahead of Eli Tomac. He would go on to lead the National series for the first eight rounds, before a crash, and a resurgence from rival Tomac, would demote him to runner up in the series. However, more success came in the 2014 season as Roczen took the opening win of the AMA Supercross series in his first race in the 450cc class. He would win one more race in the season. He would shock fans more by winning the 450cc National Motocross title in his first year, dominating at multiple rounds, and taking numerous overall and race wins. Roczen currently sits second in the 2015 Supercross series, and has already taken multiple wins. He is expected to go on to much more success in the future.