I have to say that I DO NOT think Labs make good first dogs. They need too mcuh mental stimulation and exercise. I was drawn into that when I got Willow, but she was definitely a challenge. My current Rott would have been a better choice for us as a first dog; he's very laid-back and willing to please. I think first dogs (in the general sense) should be smaller than Labs, and not as active. I'd say most first-time dog owners do pretty well with Shih Tzus if they're willing to pay for the grooming. Small spaniels, certain smaller terriers (Cairns, etc.). It completely depends on the owners.
I think the "perfect" first dog for anybody is an adult, already-trained dog, straight from his previous owners (not sitting in a shelter for weeks). Regardless of breed.