SeatGuru has long been a great resource for pinpointing the best seats on an airplane. The site has recently introduced a flight search tool, so you can plan your trip and take a look a the plane seat maps all in one place.
The new flight search, powered by TripAdvisor (which owns SeatGuru), offers the basics we've come to expect in any travel planning tool: sorting by price, finding packages, searching only nonstop, and looking for flexible dates.
A few interesting features make SeatGuru's search stand out. First, you can include baggage fees in the totals, so you can really compare how much those flights will cost. If you absolutely need power or Wi-Fi or other amenities during the flight, you can also select those options.
The search seems to be designed to give you the best view of both price and experience: You can require a minimum airline rating (from TripAdvisor's giant user community) and sort results by a unique "Guru Factor" that tells you if you'll love a flight, like it, or simply live with it. In this way, it's similar to previously mentioned Routehappy, except SeatGuru offers more detail and prices.
In short, it's now a lot easier to get not just the best flight but the best seat on that flight.