InsideTrip Informative - Inside Tip
I found this travel search engine called InsideTrip.com Unlike most search engines this one aside from finding the best price also includes very informative extras such as Speed, comfort, ease, legroom, aircraft type, best connect times and wraps it all up into a overall trip quality rate from 1-100. For example you may find a cheap flight with an overall score of 62 but for a few extra bucks another flight might be rated an 82. So why wouldn't you go for the cheaper one? Things like less legroom, high bag loss rating, longer connection times ect.. People automatically go for the cheaper fare not taking any of these things into account. This website does all that plus will calculate extra bags fees and even the cost of drinks on the flight in to your final math.
As for actually booking through the site that may be another matter. It books it through Orbitiz and as I have never used them before not sure I could recommend them. As far as just doing a search though this is the one to use.
Of course that's just my opinion, I could be wrong.