Ideal for short city breaks- travel from as cheap as £1 each way
This comparison flight checker for Europe is updated regularly. It checks 14 different airlines inc easyjet and ryan air.
found great deal on it-
Manchester to Brussels- 8/04/12 - 10/04/12 flights with ryan air only £28 for 2 adults (£7 each way each) (however be careful still had £22 administration charges) still cheap though with only using hand luggage so no baggage charge.
*Be careful though some of the cheap airlines try and add as many extra charges on as possible.
The site travel checker has great cheap deals to other cities such as Paris, Rome, Milan, Barcelona etc. depending on dates you are available.
hope this helps