I use Travelrepublic.com, sunshine.co.uk and Onthebeach.com for my research. Each has strenghts and weaknesses.
Then I book via quidco or topcashback. Every penny helps. As scunner says sunshine and travelrepublic don't break up the flights, but onthebeach do.
The latter was useful for our Easter break to Tenerife, where we got a bargain price where we fly out from Birmingham with Monarch, and fly home to East Midlands with Ryanair. Or is it the other way round?
Can't say I enjoyed Birmingham-Dalaman last year - booked through Monarch, plane supplied by Onur Air. They have a similar policy to Dalaman Airport for pricing refreshments.