Re: Free puppies?
When I got a dog a year and a half ago, I got a purebred, but there are plenty of perfectly good dogs at the pound or at PetsMart on pet adoption days (as opposed to going to a regalar pet store and buying a dog -- which I would not recommend).
Here's the deal. The primary thing that purebreds offer over mutts is predictability. When you buy a lab, or a dobie, or a border collie, or (as in my case) a boston terrier, you know what you're getting into to a certain extent in terms of personality, energy level, anticipated health issues (so you know what to be alert for), ease of training, etc., so it's easier to find a dog that matches your personality. Of course, you have to pay for that predictability.
Mutts on the other hand are probably more durable, but there is a bit more of a wildcard component to them, esp. if you can't view the parents. Some mixed breeds are really, really beautiful dogs, so it isn't like when you get a mixed breed, you automatically get a second-class dog as some dog breeders would have you believe.
Most any dog will be a great companion that will love you in a way only a dog can, so you just can't go wrong.
If you want a purebred but don't want to pay through the nose, consider getting in touch with a local rescue organization. They often ask for or require donations, but at least then you know it is going to a good cause and not just someone that is going to use it to churn out more puppies. Also, you get to help a dog in need.
Best of luck!