Kelly's Sock Class and Sable's Sock Class have been such a help to me and I have them hotkeyed on my toolbar for quick reference as it seems I am always knitting socks. I'm one of those that have done so many socks that I have a basic pattern set in my head and just knit from there and improvise at will (don't ask me about my first cable socks, it's embarassing).
I still knit them on DPNs, as it helps me keep track of where I am, especially if I am making them specifically for someone, rather than just a pair of self-striping for the kids or charity. In other words, I do it so I don't have to think about what I'm doing while I'm doing it.
I may do magic loop for casting on and the cuff since that is my least favorite part of knitting a sock. I hate Hate HATE it. Once I get past that part I'm good.