I have Craft Active Thermal tights which are super warm and fleecy on upper thigh and have a thinner fabric from just below the knee and on back of knee for ease of movement. They are nice and long so you don't get nippy ankles!

I live in the South but all that really means is that you ride outside all year, not that it isn't cold! Ridden in below 32' F and snowing and my legs were the only thing that wasn't cold. When I take off my gear there is a freezing line of red skin above where my tights end because that skin is so cold!

I also have a pair of sugoi midzero knickers. They are hot hot hot! I am getting some of the long midzero tights for this winter because the chamois on craft tights is going The midzero is a great, warm and fleecy tight - feels great and I know that they will last as the rest of my stuff from Sugoi has outlasted the craft gear. Main reason for switching brands and going with sugoi.