As a breed they've got good personality and one of the things that scientists have collected evidence suggesting that dogs that have more forward pointing eyes are seemingly more able to read human emotion through facial expression. But in terms of natural selection we've made them a species that would struggle to survive based on hunting ability etc.
Selective breeding hasn't been kind to a lot of dog breeds. I can't find the article anymore , but I recall seeing a pictorial comparison of dog breeds around 200 years ago compared to modern versions of the same dogs, complete with lists of how the modern versions had inherent problems due to their current shapes. It made me a bit sad seeing the changes in shape and reading how the selective breeding has caused so many popular breeds to suffer for what humans consider to be more fashionable dogs. But selective breeding isn't something we've isolated to dog breeds. Even things like goldfish have been bred to be visually appealing to some people, while the result typically means that many of the new selectively bred fish would be unable to survive outside of human controlled environments.
Edit. heres the thing i read
http://www.dailymail.co.uk/femail/article-4308860/Photos-selective-breeding-altered-dogs.html