An almost forgotten player outside of Detroit, Billy Sims was bringing flash to the Motor City before the more popular Barry Sanders was ever drafted. Prior to joining the Lions, Sims was a consensus, two time All American and won the Heisman Trophy in 1978 as an Oklahoma Sooner. His first year in the NFL, he ran for 1,303 yards and carried the Lion offense. After winning Rookie of the Year in 1980, he followed up with 1,407-yard sophomore campaign. He made the Pro Bowl in 1980, 1981 and 1982 and led the Lions to two playoff appearances. Unfortunately for Billy, his career was cut short by a major knee injury in 1984 and despite a comeback attempt as late as 1989, he never played again. He finished with over 5,000 yards and 42 touchdowns in a brief, but dynamic career.

Corey Dillon, Cincinnati Bengals/Patriots

The Washington Husky All American was chosen by the Cincinnati Bengals with the 43^rd pick in the 1997 NFL Draft. Dillon was a punishing runner. During his rookie season, Dillon rushed 39 times for 246 yards and 4 touchdowns in a romp over the then Tennessee Oilers, shattering Jim Brown's rookie single game record that had stood for 40 years. In seven seasons in Cincy, Dillon rushed for over 8,000 yards and 45 touchdowns, but his best was yet to come. After a move to the Patriots in 2004, Dillon set career marks with 1,635 yards rushing and 12 touchdowns. He played a pivotal role in the Patriots Super Bowl run, with 292 yards rushing, caught 9 passes for 53 yards, and scored 2 touchdowns in New England's march to a championship. In his final year in the league, he had over 800 yards rushing and a career high 13 touchdowns. A long, championship career for a punishing back that that was solid, if not spectacular, for both of his teams. Dillon finished his career with an incredible 11,241 yards rushing.

Roger Craig, San Francisco 49ers/Raiders/Vikings

The accomplishments of Roger Craig are often overshadowed by playing for Bill Walsh and taking hand-offs from a guy named Joe Montana. But they shouldn’t be. Many of today’s versatile running backs can be traced back to Craig. Drafted in 1983, Craig’s rookie season featured a back that had 1,152 yards from scrimmage, including 48 receptions in the West Coast offense. During his five seasons under Walsh, Craig would have three 1,000 yard plus seasons running the ball but is best known for being the first player to have 1,000 yards rushing and receiving in a single season. His ability to catch the ball out of the backfield made him the first real dual threat of the modern era and inspired many of today’s dual threat running backs, including Marshall Faulk and Christian McCaffrey. He finished his career with a whopping 13,100 yards from scrimmage. An exciting runner known for his high knee style.

Fred Taylor, Jacksonville Jaguars/Patriots

Taylor was drafted by the Jacksonville Jaguars with the ninth overall pick in 1998. He made an immediate impact, showing off his play-making ability with 1,223 yards rushing and 14 touchdowns and caught 44 passes for 421 yards and three touchdowns. The 2002 season featured a healthy Taylor running for 1,314 yards, while setting a then-team record with 1,722 all-purpose yards from scrimmage, including 49 receptions for 408 yards, resulting in eight touchdowns. His dual threat nature was on display again in 2003 with 1,572 yards on 345 carries for six touchdowns, topped off with 48 receptions for 370 yards. In 2004, Taylor recorded 1,224 yards and two touchdowns. Taylor’s career was hampered by injuries. However, when healthy, he struck fear in a defense. He finished his career with 13,640 yards from scrimmage, with 11,271 of those yards on the ground, highlighted by seven seasons of 1,000+ yards. Despite being limited during several seasons, he has held over 40 Jaguar rushing records.

Steven Jackson, St. Louis Rams/Falcons/Patriots

Our choice for the most under rated running back in NFL history is Steven Jackson. After setting the PAC-10 on fire for three seasons at Oregon State, Jackson was drafted by the St. Louis Rams with the 24^th pick of the first round in the 2004 NFL Draft. His career started as a back up to Hall of Famer running back Marshall Faulk. His 2005 season featured over 1,000 yards rushing, however, his jump to primetime came a season later, where he ran for 1,528 yards and 13 touchdowns. His number are explosive: most consecutive seasons with 4+ rushing touchdowns (11) – tied with Emmitt Smith; most consecutive seasons with a 40+ yard run (11); most rushing attempts by a player without a 60+ yard run (2,764); most consecutive touches without a fumble (unofficial) - (870) from November 13, 2011 through end of career and finally, the only player with 1,400 yards rushing and 800 yards receiving in a single season (2006) Jackson’s numbers don’t tell the entire story, as he was essentially the entire offense during his tenure as a Ram. Quarterback and coaching changes dot his career. Yet, he is the Ram's all time leading rusher, with 10,138 rushing career yards! To grasp his greatness, one needs to consider that Jackson played for a franchise that had Hall of Fame running backs like Eric Dickerson, Jerome Bettis and Marshall Faulk… Jackson trumps them all in career yardage!

Honorable Mention: Ricky Watters, Chuck Muncie, James Brooks, Wendell Tyler

Not convinced? Who is your top 5 most underrated running backs in NFL history? Let the debate begin!