Justin Inaz at On Baseball and the Reds and Sky Kalkman at Beyond the Box score have developed a player rating system called "Total Value Estimates" which ranks players based on a combination of hitting and fielding. It's not a perfect system due to limitations in current fielding data, but it may be the best one I've seen for estimating overall player value. You can read about the system on Justin's site.
Sky is presenting data by position on his site. So far, he has articles on first basemen, second basemen and center fielders. The Tigers rank pretty well at each of those positions with Curtis Granderson ranking third in CF, Placido Polanco fifth among second basemen (thanks largely to his defense) and Muguel Cabrera seventh at first base.