Best Fantasy Football Running Back?

I'm going to be taking a running back in the first round I know, but I just don't know which one. I've already got Rudi Johnson. Who is the best fantasy back available that will get the most points?? Joesph Addai (IND), Willie Parker (PIT), Brian Westbrook (PHI), Laurence Maroney (NE), or Ronnie Brown (MIA)???