The knock on Jamaal Charles coming into the NFL was that he was simply a speed back. In replacing Larry Johnson at the end of his second season, Jamaal proved that he was more than just a speed guy, and he's continued to prove that by rushing for over 1,000 yards in each of his last five full seasons (minus the ACL year in 2011).
NFL Network's top 100 players ranking understands this and puts Jamaal Charles at No. 12 in the NFL.
The fact that many people will call last season a "down year" for Jamaal Charles is precisely what makes him special. Five yards per carry is a "down year" for a player of Jamaal's caliber, but it's one of the best averages of the year for any back. His 14 touchdowns -- down from 2013 -- still tied for the lead in the AFC.
Others will mention excellent backs such as Le'Veon Bell who was ranked No. 16 on this list. Note that Bell's 4.7 yards per carry is nearly a yard and a half higher than his previous season -- and it's still a lower average than Jamaal's worst season. Bell's 11 touchdowns are also less than the 14 Jamaal scored in his "down year".
So the time for comparisons to lesser backs is over. For my money, Adrian Peterson and Marshawn Lynch are the only two backs that compare. And even then, you could say Jamaal has more left in the tank than either of them.