I'm going with AussieTravelCover. We have family friends that are TA and we try to buy our long haul ticket with them (usually there is about a $20 difference between them and the on-line prices...but they are family friends!) and we get our
travel insurance through them as well. They give us a significant discount on the insurance...it is even cheaper than the on-line price if we went direct.
For the US, we normally buy the top cover available. For the age group that we are in (80 and under), I think ATC have a $100 excess for some items but it is nil for the ones that I want to be covered for; a 24 hour 1800 contact number and have never quibbled when I've needed support for medical cover.
It also covers for cancellations beyond your control (not acts of god), lost luggage and theft.