I swear to god, my absolute favorite socks (and I've tried MANY, MANY pairs - mostly for running though) are the polyester socks that they sell at Wal-Mart. They're rock-bottom cheap, hold up great, and work 100% as well as the uber-fancy ones I've tried.

I put these thru the wringer as a runner too - I ran (not biked) 80-100 miles per week for several years for most of the year, and these were my go-to socks at all times. I bailed on all my Wrightsocks, Nike socks, Adidas socks, etc. and preferred these in the end.

I'm rocking them on cycling now for 5-6 hour bike rides every Saturday, and have had no problems.