In response to Ash's request here I'm starting off a thread for inclusion in the key posts on useful links for travel. It might be a little all over the place at the moment but I can do a tidy up when time permits They may well also be included in other key threads.
This is a list that I compiled for myself from AAM posts but might be useful to all. Feel free to add others:
I've searched for flights using these then gone to the individual airlines' websites to get better deals. They don't seem to search all budget airlines' offerings though (e.g. Ryanair).
I have travelled long haul many times in the past few years, I recommend www.A1travel.ie, and [broken link removed]. both very good and no difficulty with sterling etc.