Carl Peterson was ranked #16 on a Forbes list of best GMs. Here is their criteria:
Forbes.com's first-ever proprietary look at GMs in the NFL, NBA, NHL and MLB grades each GM on two yardsticks. First, there's the performance (regular season winning percentage and postseason wins) during the GM's tenure versus the performance of his predecessor. Second, there's the GM's relative (to the league median) payroll compared with his predecessor's relative payroll.
See the whole list here.