Below are links to some of our favorite websites for checking flight prices.
Google is good for finding flights based on which day you want to travel. Hipmunk is better if you want to make sure the times are just right. Priceline is good for bidding on flights. Southwest's flights don't appear anywhere but on their website and is good when you carry a lot of luggage, because bags are free. Spirit is quite the opposite. Bags and several other things are not free, but they have ultra low fares. Most of the time, even after fees, Spirit will come out the winner. Their site will offer lower fares than if you book from a site like Priceline. This is why it is always a good idea to check the airline's website if it's cheaper than what a site like Priceline or Kayak says.