Still, I have my clear favorites. One completely reliable liner sock is the Wigwam Coolmax Liner ($5). A great liner sock for winter or summerwicks well, dries fast, and has good anti-blister characteristics. Another good sock is the Patagonia Capilene IV liner ($12), which blends Merino wool with Capilene. Merino is a good material for socks because it absorbs and holds a great deal of moisture, keeping it away from your skin. But, carrying a spare is a good thing as they are a little slow to dry. SmartWool makes a mostly-wool liner for $9.50. I love SmartWool socks, but in this case would suggest the liner might be best for cool-weather trips. Or, carry a spare.
For long trips, I've also had good luck with the Fox River X-Static sock ($8.50). These socks combine a polypropylene base fabric with specially treated nylon that inhibits the growth of fungi, bacteria, and other nasties. So, you're feet smell sweeter longer, and won't offend your tent partner.