alot of coaches are different, I'm sure everyone will say their teams coach is the best. The most well respected coaches are those from the perennial power houses.
Coach Mike McShane - Norwich
I've heard Emery from Plattsburgh can be hard on his players "tough love" if you will, but he gets results.
I will say this tho, having watched Bob from Day 1 at Plattsburgh to now, the whole "tough guy" coach has really really mellowed. Especially since his kids.
Are there any to avoid (aka Torterella types)?
If you're on a D-III board, it's obvious that making the NHL and even the AHL is a long shot, at best.
Pick the school where you'll get the best education that will prepare you to enter your chosen field. Hockey should not be the primary reason you attend a particular school.