Alaska Airlines provides flights all around the Americas and often has very competitive prices. Compare them today to get the best deals.
One situation I was in was that I had arrived in Seattle after flying in from Frankfurt, Germany on US Airways. I was extremely tired and jet lagged, and I knew that the last Alaska Air flight that night to BC was at 9:00 pm. I didn't have a ticket, and didn't arrive until 8:30, and still had to pick up my luggage (suitcase, massive backpack, and mountain bike!) and then buy the ticket, check in, go through security again, and get on the plane. All within 30 minutes.
I managed to get my baggage quickly and raced up to the Alaska Air sales counter. The gentleman was extremely helpful, and got me a ticket on the last flight that night to Kelowna, BC. He guaranteed I could get on the flight, but said my luggage might have to be sent the next day - I was fine with that.
Even though I had trouble going through security (I always get "randomly" searched) Alaska Air held the flight for me an extra ten minutes to make sure I could get on it. And when I finally arrived home, my luggage had made it on flight as well and everything worked out perfectly!