I am most definatley biased. But, I will give my .02. My suggestion is that if you can get, and handle, two, do it! I have two and they are best friends. They keep eachother company and miss one another when they are not around. They sleep side-by-side and if I could do it all over again, I would! I love having two dogs. One is in the avatar. They are pure bred German Shepards. We picked them out at 3 weeks old and picked them up at 6 weeks. They have been with us ever since. They have GREAT temperment, are very friendly and loving and as I said before, best friends. They came from a litter of 10 and they are sisters. Neither is the Alpha, they are content to share. They are almost 80 lbs each. One is names Copper and the other is Gotti.
All dogs have a natural tendency to be loving or mean or whatever. A lot of it, however, has to do with how they are raised. If you are consistant and strict, you will have an obediant loyal friend. I went to a repuatable breeder but somethings you can't avoid. My dogs just happen to be alergic to black ants and cats so they scratch a lot. For bigger dogs, ask for papers on their history with hip problems. If you get a purebred, get papers on them. I have the history of my pups going back 5 generations. The father was from Brazil and the mother was from Chile. Made for some interesting pups. Some are all black, some are black and red, some black and white. Crazy how that stuff works out! Anyway, I had a bad expirence with a shelter dog, I can explain later. I have a LOT of GREAT books on how to pick out the kind of puppy you want (like how to predict their temperment, etc). If you want, you are more than welcome to borrow them. I did a LOT of research before I got my pups. They are 2 1/2 now and I can't imagine life without them.