As most people have already said, a rescued dog is the best kind of dog to get.
I would like a dog to look after one day and I think the perfect breed for me would be a Labrador/poodle cross. A Labradoodle. Not because it has a funny 'oodle' name or is fashionable but because to me they are the ultimate dog. All the gentle family nature of a Labrador with the added lack of body odor or excessive shedding of the poodle. I hope I can find one to rescue when the time comes (not that I hope that it will have to be rescued!), but I think they are pretty desirable dogs and generally they don't seem to end up at shelters.