If you need insurance for visa requirements, we use AXA. Easy to deal with, well accepted, never had to make a claim.
If you're buying insurance for the sake of evacuation, I'd think twice. My wife and I have both been hospitalized in foreign countries. Had we chose to evacuate, which the medical centers would support as you are an unknown commodity payment wise, I'd be dead and she would likely be paralyzed on one side. As it turned out, we're both fine.
In my case, in Italy, my surgeon was a chaired professor at the Univ of Pennsylvania and his team had all done their residency at the Cleveland clinic. In my wife's case, in Switzerland, she was speeded to a neurological center about an hour away and had a team of 11 doctor's from all over the world. She went in paralyzed on one side and came out just fine. A rare disease we didn't even know she had.
Once back home in the USA, she went to a leading med school for further examination. The only doctor that had a clue about her condition was a German that happened to be visiting that week. There's nothing wrong with medical facilities overseas.