I raised and trained springer spaniels as a kid as bird dogs and they do that job perfectly.
As previous posters stated the dog you're going to use really depends on what you're hunting. I breed Rottweilers and Shepards now and they are great dogs as well. Shepards do well with tracking but they are a herder so by the time you catch up to your game it will be half destroyed because they tend to play with prey.
Rotties are better for bigger game like hogs. They have the stamina to outlast them but not the speed needed for most small game.
Truth is "any" dog can do "any" job. It just depends on their temperament and how easy it will be to teach them what they need to do. Hounds and retrievers are great hunters because it's what they've been bred for. It's in their genetics. But don't let someone tell you that you can't use a Rottie for duck hunting! I use mine!
Check him out at www.backwardsdog.com
he's the boy in the "about the trainer" section.
Also, they take ALOT of work to get good but some of the best hunters I've seen are Weimaraners.