One of the annoying thing you should try to avoid when buying a house is aircraft noises. And the best way to find out more information would be to find out all the flight paths for the airports in your city.
There's this web site which shows the flight paths and noise levels from different monitors. Click on "location" on the left hand navigation bar, pick a city and you can see the current flight operations on the browser(with 40 min delay for security reason).
I found it quite interesting watching so many planes coming in and out of the airport. As shown below you can also have a clear view of the flight path for different aircrafts.
As shown below in the yellow bubble, whenever an aircraft approaches the sensor, it will change colour and show the noise level.
Wonder if there's services like this for other major international airports. Would be interesting to see the flight paths for all the very busy ones like New York or London looks like...