(Sorry, bad pun).
Janet recently started a great thread about socks.
Her timing was brilliant for me because I had just been fretting about my paucity of knee highs. As many of us have noted, these are a new necessity with the wider leg trousers if you live in a cold or even cool climate.
My favourite gear and more-than-gear store (Altitude) always has a Black Friday week sale, so I decided to try out a new-to-me brand of trouser socks. The sale was substantial so I ordered a bunch. They arrived today and I put one pair through its paces (ha ha again...my 10,000 steps in disgusting weather). I have to say I am very impressed!!
The brand is 1177.
I'm usually an Icebreaker or Smartwool wearer but their knee high selection leaves a lot to be desired, at least in the thinner trouser sock department.
I was skeptical about these, because they are not wool but some man-made fabric.
But...wonder of wonders...what they claim on that website is totally true! Your feet don't sweat or get cold. Or at least mine did not. (These styles would not be warm enough for -20C but that is not what I am talking about.) It was a cold and extremely rainy 6 or 7C in Vancouver today -- felt much colder, to me -- and I wore these with my waterproof Cons. Those shoes have Goretex lining so they sometimes become uncomfortably warm indoors, even with breathable wool socks. Today, though, I felt perfectly comfortable inside and out.
Meanwhile, the fit of these socks is spectacular! There is a right and a left foot! The heel is constructed so that it stays on your own heel (even if narrow, like mine -- and you know, I have SERIOUS sock slippage with most brands). The leg portion does not slip down but it does not feel in the least constricting and it doesn't leave a big red mark on my leg where the top elastic is. The sock is thin enough for dress shoes. And it comes in a ton of patterns and a few plains.
Of course I can't vouch for how well or how long they will wear, but I am extremely pleased so far and would recommend them. I ordered size small for my 6.5 / 37/ 7 foot.
ETA: Thanks for other recommendations, all. A little update -- they are not completely perspiration free -- I guess you can't have a synthetic sock that doesn't sometimes create that problem. And they are not the warmest. But they do fit, stay up, and are washing well. And comfort level higher than some other synthetics I have tried, for sure.