Being from Vegas, the weather is usually not conducive to boots, so I'm a little embarrassed to say (as a twentysomething) this is the first pair of boots I've owned.  However, I've been pleasantly surprised (and perhaps spoiled) by how ridiculously comfortable these things are.  I got these from a shoe store (not Amazon) but came across this page because I am considering getting the same style in a different color and they are also cheaper on Amazon than I have seen them anywhere else.

The boots are completely lined on the inside by fur, even on the sole of the foot.  They are very warm, but not too warm for a Vegas winter.  I have been wearing them to go out in, and have been impressed by how cozy they are.  I almost don't want to take them off when I get home!

The main negative is the fit is a little loose on my legs, but I've always had stick legs, so it's probably just me.  I would, however, suggest sizing down if you're a half size (I'm usually 7 1/2, but the 7's fit much better than the 8's).  This was suggested to me by the shoe store employee, who told me the fur flattens out with time.

These seem to be of very good quality and although a little pricier than some of the brands I've seen in department stores, the materials are better (real fur, suede) than a lot of the cheaper alternatives.  There's also pricier brands that seem to be of nearly identical quality, so I think this is a happy medium.