Chris Johnson is the number 1 pick in any fantasy draft on the planet earth. Any pick otherwise would be a classic case of over thinking. Johnson was worth roughly 68 points more than both Adrian Peterson and Maurice Jones-Drew who were the next back running backs. With nearly 2300 total yards and 14 touchdowns, Johnson single handedly took many teams to the playoffs.
Your next choice comes down to either Jones-Drew or Peterson. Both ended up with roughly 270 fantasy points in 2009 and are due for another great year in 2010, but there are a few concerns. Jones-Drew's scoring was up and down all season. Peterson's explosion was curtailed despite the brilliance of Brett Favre. His fumbling has also become more than just a concern. For number 2, I give the edge to Adrian Peterson.
At number four, Ray Rice is an easy pick. With over 1900 yards and 8 total touchdowns, he etched himself into a tier by himself. Rice is a bonafide stud as evidenced by his double digit points in all but two games. As an added bonus, he proved durable, never missing a game. With a good nose for the endzone, you can expect a couple more scores as Baltimore's feature back along with the same amount of yards.
Thomas Jones finished the fantasy season ranked 5th in points, but his value plummets for next season as Shonn Greene's emergence can't be ignored. Also, Jones will hit 32 by the time next season starts.
A mover in the other direction is Darren Sproles or possibly another replacement for Ladainian Tomlinson. San Diego will almost assuredly dump the former great for greener pastures. With a powerful offense and a gift wrapped running game, whoever takes the majority of the snaps will be a fantasy star.
Of course, Miami's prolific running game can't be ignored. Before he went down, Ronnie Brown was on a ferocious tear. With the team depending on him the rest of the way, Ricky Williams was awesome and somehow finished sixth overall. Either player would be a nice addition to your fantasy squad, but of course you must account for the split workload. If both are healthy, neither should fall below the fourth round.
Other top considerations include Frank Gore, Cedric Benson, Steven Jackson, DeAngelo Williams, Jonathan Stewart, Michael Turner, Pierre Thomas, and Jamaal Charles. Be sure to keep an eye on offseason movements for changes in the rankings.