This is possibly quite goofy, but I got my 16 year old a Slanket for her birthday and she was thrilled. The Slanket is an extra-large blanket fitted with sleeves to anchor it while you lie back on the couch. She is quite certain that our house is insignificantly above freezing in the winter, so she’s always cold. Not anymore!
[Since we reviewed this item in 2006, several incarnations of the blanket-with-sleeves have emerged. Gizmodo published an excellent comparison review. Slanket, while a satisfying product, is one of the more expensive versions. -- SL]