IMO, Sanders, Payton, Simpson, Faulk & Dickerson.
Yeah, I nixed Sayers & Peterson for not playing long enough. And I always argue that Brown's dominance MAY not translate to different eras. If Sanders was playing today, he'd still be the most agile RB in the league, making defenders look just as silly as he did in the 90s. Not sure Brown would be bullying today's players like he did in the 60s.