Until now if you wanted non-stop travel to Istanbul from the U.S. you had to depart from Chicago, New York, Washington DC and Los Angeles. You can now add Houston to that list. Turkish Airways began non-stop Houston to Istanbul in April 2013. They were voted best European airline by Skytrax.
It is about a 12 hour flight going East, a bit longer coming back. As of now they have three flights a week but we expect that to grow.