Oddly enough, I was sitting here sipping some coffee out of my relatively new Thermos brand mug and saw this thread. I think my wife got this from Amazon for around $25.
No handle (which I prefer) a sealing top that can be disassembled for cleaning, and it keeps liquids hot for a long time. I'm not sure about 8hrs, because I'm usually drinking it the whole time, but if it were filled, closed and then left for several hours I'm sure it'd still be plenty hot.
As and added bonus, the surface takes a sticker really well. The only thing I don't care for, and the reason for the sticker, is that the top is symmetrical and it's not easy to tell where the front is. I poured hot coffee on the side of my mouth several times before I added the sticker. It looks better with the sticker anyways!
