Bob Sanders is better when healthy. I'd venture to say Bob Sanders is our next Rodney Harrison, Brian Dawkins, but that's just me. The guy really makes a difference in football games, he lays some lumber, fills lanes for takcles, not so much the interceptor if you league values that moreso. He just consistently makes plays.
Roy Williams should probably be the pick due to 5 straight seasons without injury, but if you want the better producer when healthy and are willing to take chances then Bob Sanders should be the guy.