We're about halfway through December, and the mattress deals are still going on. In fact, this weekend we found the best discount of the year.

For a limited time, GhostBed is offering 33% off sitewide with coupon code "GHOST33." In addition, any mattress purchase comes with two free luxury pillows ($170 value). This is the largest discount seen on the entire GhostBed site.

If you're looking for the most economical buy, GhostBed's sale of $767.15 (queen) with coupon "GHOST33" is definitely the cheapest mattress on sale, at $378 off.

But it's the GhostBed Luxe that ranks in our Best Mattresses guide. The 3-inch-deep luxury foam mattress is packed with next-generation cooling technology and is known as the coolest mattress available. The top layer consists of a comfortable quilted cover made of breathable fibers. It also contains memory foam gel that neutralizes body heat. After coupon, the GhostBed Luxe is $767.15, $378 off.

The coupon is only valid through December 14, so grab this deal while you can.