Aaagh!
AB has done it again!
The last link should be
http://www.wizzair.com/
Alternatively, most airport websites have a list of destinations, served by both full-fare and budget scheduled services, on their websites. (For airports operated by BAA, click 'Flight information' and then 'Destinations & airlines').
The reason I suggest starting with the airline (or airport) websites, is that there's not much sense researching a particular destination if you can't get there easily from where you live. (Someone recently posted a very similar question about a weekend city break for their parents. Since their parents live in Tyne & Wear, it made sense to check the flights from Newcastle & Tees Valley airports. That showed that the only realistic alternatives were Prague, Barcelona and Rome. It would have been a waste of their time to research other destinations).
Chris