Here are the top 10 list per the consumers advocate insurance. Oftentimes they have a waiting period of 15 days before a claim and 12 months for hip dysplacia. You also have to start early as existing conditions will not be covered.
If you are getting for an older dog don't bother as most everything will be considered preexisting. If it is for a new pup the sooner you get it the better.
I just finished researching this for the boys. Before you decide to get pet insurance read, read and read some more. One even said if you have the insurance 1 day or 5 years if you move the insurance null and void. I would recommend self insure. Start you a saving account and set money aside. I just knew if I bought it I would go into insurance hell to pay a claim. My opinion self insure....