I've just got to get in on this one... . Lots of good points brought up by everyone. First, I propose we just look at this from another angle; energy level of the dog.

High energy dogs include;
Border collie
German shorthair pointer
English pointer
Visla
the field hounds (coonhounds, ect)

I know there are more (maybe someone else can help with the list) but the key is that these are field or working dogs; dogs that are bred to work 8 to 10 hour days. Notice my avatar; I was ready for the amount of energy that I was about to unleash (pun intended) on my family, but the rest of my family wasn't. She is almost 5 and she still needs to be worked HARD pretty much every day. The only time she is at "ease" the entire day is when we are training, backpacking, or hunting all day. By contrast, a Rhodesian ridgeback will typically be a couch potato the rest of the day with 30 to 40 min. exercise once an adult. So it is important to understand what the requirements of the dog are that you pick so you understand the training/exercise time commitments that go with that.

Second point, already been made, is don't get a dog bred to chase down game like a Beagle or Coonhound. Even though Beagle's are small, they are pulled by their nose and love to hunt (but not listen). Great if you want to hunt rabbits. Coonhounds are beautiful dogs. But again, they are like a big fast beagle. You need to be able to train the dog to NOT chase that deer or whatever if need be. It can be done with these dogs, but it is much harder. And as James said, last thing you need is a large dog dragging you down the trail after something it wants to chase. Heck, even a medium sized dog can lead to a sprained ankle if it catches you unaware.

Females over males (in general). They tend to wander less and be a little more family oriented. (My favorite dog ever was an intact male black lab.)

Don't pick one of the alphas (male or female) of the litter. Pick one from the center of the pile...NOT the bottom either. Usually a little less training drama from this zone although with the other alphas gone it may decide to fill that slot. You must make sure that the dog realizes that you and your wife are the alpha pair and will not be giving that spot up anytime soon.

Probably tooooo much info so I will stop. My gsp is a great dog...basically any dog you pick will probably work out for you AS LONG AS YOU PUT THE EFFORT INTO TRAINING AND DEVELOPING A RELATIONSHIP WITH THE DOG. That is probably the most important thing for you and your family to take away from here. So how much work are you willing to put in the first 3 or 4 years?

With Tica it was 3 hours a day for the first 2 years...now its just 2 hours. Smart and energetic means more time otherwise destructive behaviors start. A lot of intelligent high energy dogs will not listen if they sense that they are stronger minded than their owner, however they will also not respond well to harsh discipline. You have to be calm, confident, and consistent with these breeds through out their lifespan.

border collies...check this

Seriously, read this.