Alaska Airlines has a good Cyber Monday sale. They operate mainly up and down the West Coast, but there are also some good sale fares to Hawaii from many cities. The deals are good today only for dates between December and mid-March. The lowest fares are good for Tuesday, Wednesday and Saturday travel only and require a 21-day advance purchase. Alaska also has service to many locations in western Canada and leisure destinations in Mexico. Not to be overlooked, Alaska serves many cities on the East Coast, such as Newark, Boston, Washington DC, St. Louis, and Orlando, although typically with limited service (one or two flights a day).
You can visit the Alaska Airlines Cyber Monday page to find the sale fares for your city.
While Alaska Airlines has an excellent frequent flier program (Mileage Plan), they also partner with many other airlines including Delta and American. So, if you are a member of these programs, you can get mileage credit for your flights on Alaska.
UPDATE: Alaska Airlines tweeted a coupon code that can be used for an extra 5% off this already great offer. Enter SHOPNOW at checkout to save!