I have been running last 10 years tried so many different socks.
I picked up these socks 4 years ago and ran about 10 full marathons and  about 6 sprint triathlon with the socks.
This is by far the best. Comfortable, heavy duty (last more than 1000 miles running)
and of reasonable price. They are easy to put on, which may be important for some of the triathletes.