Travel Guard is one of the largest travel insurance companies in the United States and world. They are backed by parent company AIG, which is one of the world's largest companies and insurers.
I have used Travel Guard several times in the past because they are contracted out with Expedia whenever you book a trip through them.
Personally, I have mixed views on travel insurance. While the cost is usually not too overwhelming at usually 5-10% for the total trip cost, I feel like it is just another way for someone to make extra money off of me.
Granted it does give you protection against any unforeseen emergencies or cancellations you may have leading up or while on your trip, but of the several times I have used it I have not needed to use it.
From what I have read from other people's experiences though, they do pay out fairly for any claims you might ever have to make, so that is a definite plus to know that you will get what you deserve out of the deal. I am sure that the people on the recent cruise ship disaster that had travel insurance are sure thanking their lucky stars right about now.
Given that most airlines and hotels no longer give grace periods or full cancellation refunds, I do believe that if you are taking an expensive international trip that has many destinations that you would probably be best off getting travel insurance. Most health insurance companies do not work well overseas and travel insurance covers all emergency situations so for that alone it may be worth it for some people.
It really is a matter of preference, would you rather be safe then sorry or go without insurance?