Glad some of these people aren't GMs.
I think I'm going to go with the guys who don't allow their players to play sloppy football. The mistake-free teams are the teams with the best discipline. Good discipline is inherited from hard work, which in turn is derived from strong motivation.
So I think Tom Coughlin, Jeff Fisher, Andy Reid and perhaps Mike Tomlin would be my top choices. But Tomlin needs to prove he can do it without beast coordinators.
People can say Couglin's ring is a "fluke" all they want, but he was a pretty good head coach for the expansion Jaguars; also, while he's a hardass, he proved that he is willing to change his ways in order to make his team better. That's the mark of a good coach. He also surrounds himself with good staff members like Belichick does.
Fisher consistently gets his men to play better than they should be playing. I think his weakness is finishing off what he started, as evidenced by the Titans' loss tonight. I'd still take him over most of the other coaches in the NFL.
Reid is a great all-around coach. His teams commit few penalties, rarely beat themselves, and are constantly being infused with excellent young talent. It'll be interesting to see how much influence Jim Johnson had on Reid's Eagles, and whether Reid can maintain their defensive production over the next few years. Regardless, the Eagles are in contention year in and year out.