For the average "pet home" who will do little to NO hunting and little to NO formal obedience training, and needs and easy to train dog who is friendly to everybody, good with other pets, and good with children, the Golden Retriever is probably best. The Labrador is probably my second choice - but will be MORE active.
While GSP and Weimaraners can be good dogs in the right (experienced) home, both (German origin breeds) are FAR MORE PROTECTIVE, and require far more aerobic daily exercise & a "job" if not used for actual hunting. Do not get one if you want a half DEAD "bear skin rug" on the floor or a pink flamingo "yard ornament". It won't going work, out well for you - AT ALL!
In fact, Weimaraners and GSP can run the legs OUT FROM UNDER any Lab. They were bred to run FOR HOURS - looking for birds; not "sit" in a blind or boat waiting for something to BE shot.
Both breeds are exceedingly BRIGHT (problem-solving breeds) and if you do not FIND something for them to DO (to challenge them mentally) as well as give them enough daily (aerobic) exercise - they will find something to occupy themselves with, - you may not like. They were both bred to be versatile hunting dogs able to point track and retrieve game and they excel at many AKC dog sports like: tracking, nose work, barn hunts, lure coursing, dock diving, hunt tests, agility, rally etc. The only thing you CAN'T DO with a Weimaraner ...IS NOTHING! Our favorite mantra for new owners is; "a tired dog is a better behaved dog - what choice does he have?"
The Weimaraner is the largest, and can run 85 to 90 lbs in large (still in standard) males. This size dog (if not trained to heel) can DRAG YOU...... after a squirrel or cat and into the path of a car. Plan on giving the dog some early, formal obedience training (for your OWN safety and well being)!