...the best all around hunting dog is the jagdterrier:
http://en.wikipedia.org/wiki/Jagdterrier
...they can do everything; track (blood trails for injured game like deer), locate (anything from bird hunting to varmint hunting), retrieve (both water and upland birds), and do all the traditional things that terriers do...but, they are considered good at all around but not great at any one thing...if I did a lot of different things I'd probably get a jag...