my favorite airline website is cheaptickets.com, they are always the least expensive and they keep track of your flights thru the years. I've been using them seen 2008. Also, Hotelscheap.org is another great site for savings.
Some of my favorites are Travelzoo & Kayak. Also I try to use Southwest when I fly... They're inexpensive, my checked bag is free, and if I need to rearrange my flight times I can make adjustments without a fee!