I have some of these bamboo socks. They are thin, wick well, not expensive, and have good anti-microbial properties.
However, I have been wearing my Combat Touring Boots for 14+ years now. I put some Spenco insoles in them when new and still have the same pair in there. The insoles provide excellent cushioning. I just wear plain old ordinary mid-calf athletic socks. The cheap, cotton kind you get at JC Penney's for $12 for a 6 pack or whatever. The bamboo socks referenced above get used sometimes when I'm hiking or on the racetrack - but mostly I just don't bother wearing them. They're too thin to wear by themselves for most of what I do.
I have certainly done MANY days where I rode some and walked around a LOT in my boots. For example, pretty much every year at Daytona Bike Week. After the first month with these boots, I have never gotten a blister or even thought I was going to get a blister. So, I'd have to agree with some other posters - it sounds like there's something wrong with the size of your boots.