Maybe it's the influence of the movies, but almost everyone who's looking to get a dog wants the young and cute puppy rather than the older or even senior companion. What most people fail to realize is that with an older dog, you get all of the joy and much fewer of the nightmares. Here's why: 
Older dogs, especially when adopted from responsible and devoted breed rescue clubs, almost always come with much more predictable, and often more calm, dispositions and tend to have greater flexibility than puppies. In other words, they adapt more quickly to a new home and are much less likely to eat your leather couch in a fit of separation anxiety. An older dog is more likely to attach to you quickly and become the epitome of "man's best friend". In other words, an older dog has the experience to appreciate a loving home, especially one where he's allowed to sleep on the couch every night (like at my house) unlike a puppy who's still figuring out how the world works and will push you harder to see how firm the rules actually are. With an older dog, when you meet him/her and spend some time together, you're likely to get a much better idea of how he really IS and how he will interact both with you as the owner and with new human friends. You won't need to spend any time figuring out how large he'll be when grown or how hyper, how good with kids, how cat-friendly, how good on the leash or how devoted and social. What you see is really what you'll get, in almost every case. By way of example, let me tell you about our Weimaraner, Buddy. When my husband and I started looking for a Weim to adopt, our adoption counselor told us, after hearing what we were looking for, that she knew the perfect dog for us but "you won't want him; he's too old". After talking with Buddy's foster mom, we decided to take a look. Buddy is 11, which is certainly not a youngster by Weim standards or even within that category of "older" dog. Buddy is clearly a senior citizen. But one look at him and it was love at first site. Let me tell you what made Buddy the perfect dog for Ken and me and why we consider him the best dog on earth. (Don't tell his sister we said so!) Buddy has always lived indoors and has perfect house manners. He would never potty indoors or chew any of our furniture or belongings. He's very sweet and devoted to both of us, great with the children of our friends, mostly ignores our cat and is protective of us without scaring our friends or the postman too badly. He only barks, other than as a warning of someone approaching the house, when he's hungry or needs to go out. He's great in the car and on a leash. We had only had him a week when he rode with me to Tulsa for a funeral. He has some arthritis and was overweight when we got him but is much slimmer now and is doing great health-wise. The only behavior you can remotely call "negative" is that he has the tendency to stand in front of and stare at anyone who occupies his spot on the couch. Otherwise, he's perfect and we love him very much. I guess an argument could be made that, because of his age, we can't expect him to live more than a few more years. Ken and I, however, are convinced that Buddy deserves to have a loving home where he is spoiled just enough and we feel lucky to have him. We adopted a female, Daisy, shortly after getting Buddy and he's taught her a lot about being a good house-dog and she's reminded him how to act young. They really do great together. Daisy, Buddy's "sister", will be four in April and has all of the characteristics of the older dog I've been describing, she just acts somewhat younger than Buddy. She has convinced us that the best dogs to adopt are those at least four years old. Buddy is the proof that there's no limit to how young a dog should be to be a perfect family companion.