Cousins was followed by Jacksonville (Miss.) Piney Woods power forward Renardo Sidney, who gave Cousins competition for the No. 1 slot in the rankings.
"It was a two-horse race for No. 1 between DeMarcus Cousins and Renardo Sidney," Rivals.com national basketball recruiting analyst Jerry Meyer said. "They're both skilled power forwards. They're that same type of player."
The 6-foot-9, 234-pound Cousins' strength, athleticism and size put him into the discussion for the No. 1 spot, but his explosiveness and ability to play in transition separated him from the pack.
"He's an inside and outside scoring threat," Meyer said. "What stands out about him is how good he is in transition. He can do things going full speed to the rim."
Sidney also stood out as a power forward who can excel as a passer. During the AAU season, he was able to get the ball to center Kevin Love, the No. 7 prospect in the class of 2008, on a regular basis.
"You can run the offense through Sidney," Meyer said. "He's similar to Cousins, but with Cousins there's a little more athleticism. Renardo isn't quite as explosive, but he's a skilled player. When he was teamed up with Kevin Love, he did a great job of feeding Love the ball down low."
Sidney was followed at No. 3 by another power forward, Derrick Favors of South Atlanta. Brooklyn, N.Y., shooting guard Lance Stephenson was the highest ranked guard in the class, checking in at No. 4.
Richmond (Va.) Patterson School power forward Karron Johnson was ranked at No. 6 followed by Elizabeth, N.J., shooting guard Dexter Strickland, Indianapolis Lawrence North power forward Stephan Van Treese, Oklahoma City shooting guard Xavier Henry and Lovejoy, Ga., small forward Noel Johnson.
"At the top you have a lot of good power forwards and then your guards are guards with size," Meyer said. "It looks like the 2009 class is going to be a good class, especially at the top. The 2009 class might be better than the 2008 class."