There are so many factors to consider when looking at breeds.
Drool
Children
Other Pets
Grooming
Excitability
Exercise
Climate
Activity level
Health Problems of the breed
Training requiired
Etc.
Purena used to have a nice little test for potential owners, but I am not sure if it is still avaialble. Plus, I remember it gave me answers I was appaled by - I don't want a Peak.
This book is mentioned a lot.