A good robe will make you want to stay home all day, which is probably not the best thing, but in the winter for weekends and holidays, they can't be beat.
I have an awesome one from my trip to Bali 2 years ago, but I hardly ever wear it. I should start, especially now that I work from home.
Here are 3 comfortable and attractive picks:
$95 Microfiber and terry spa robe
I like the contrast lining on these. The dual layers would be very warm.
Spas really do have robes just like this, and they feel luxurious and heavy in a nice way.
$178 Silk Cashmere robe
This pink color is terrible, but there is a really nice graphite color that it also comes in. Imagine how soft it would be. And it drapes well over your body and the side tie and diagonal across the front elongates you so you don't look like a lump.
$80 Ruby velour robe
This one also has the side tie. The velour is a love it or hate it thing, so if you are buying this as a gift, be careful!