Picking a unit takes a bit of work, but once you have it down your done. First, YOU have to define best. Some states and species I'm much more interested in just getting to go than I am getting to hunt in a 'trophy' unit. Carter's Huntin Fool is a good place to start, especially if your focus is on trophy units. Otherwise, pay attention to hunting message boards and ask questions. You'd be surprised at the info you can glean from these boards.
Does that help?
