Oh, Slanket!
My housemate derides my slanket (indeed, initially attempted to ban it from the house), but I say: anyone who thinks a slanket is silly has got the heat on too high in these hard times. Our 1895 row house is more than a tad drafty, and the slanket is superior to any alternative I've tried for watching television, reading, or working on the couch.
No, really. It retains heat better than a sweater (because it shares all your body heat, not just the bits under your sweater or jeans), yet lets you do everything you need to. Yes, I know I sound like I'm acting on an infomercial. That's because the slanket is actually as awesome as they claim. Also, it sounds like a Tudor insult. Add me to the ranks of the proud slanketeers.