I love you.
In general Kayak.com is my favorite place to start researching trips. I like that it gives a wide variety of options by searching multiple companies. There are also sliders to narrow down take off/landing time on each flight, length of layover, length of trip, and my favorite- price. If that's not enough for you there are also check boxes airlines, number of stops, and type of aircraft. All of this means it's easy to find your most perfect flight/fare combination.
The new additions since my last fligh have me even more excited. It will calculate baggage fees and add them to each price, giving you the true ticket cost. There is also this handy chart that outlines all of the airline fees. Will a free snack make or break your flight? How much will enough leg room cost you? And of course those baggage fees.
If you're thinking about taking a trip and have the money saved up this is a great time to fly. Two years ago the tickets I just bought for my trip would have been in the $350-400 range. Direct flights from the Rockies to Philly and then back from DC, booked just under 3 weeks in advance cost me $276. Depending on what I do baggage wise I'll be $19-49 under my budget. I could have gotten things down $26 by taking a flight with a layover but at this point getting in early enough to have dinner with my husband and make it to work the next day (not to mention 3 hours of my time) are worth $26 to me.
This isn't a sponsored post, I just love the service and it has continually helped me to find the best fare/flight combinations time and time again.