Below is a list of Airlines flying to Valencia city airport......... More airlines are flying here all the time. This list is only the most popular carriers.
British Airways. NEW now flying Gatwick and Birmingham to Valencia through out the year
Ryan Air - The undisputed king of discount flying. From Valencia, they fly to a lot of locations covering most of Western Europe: Portugal, Ireland, England, Denmark, Sweden, The Netherlands, Germany, Belgium, France, Switzerland, and 4 cities in Italy. More routes to Valencia being opened all the time.
Vueling ES - This company is new to me, and is based out of Barcelona. Their fares are low and from Valencia, they fly to Amsterdam, Brussels, Paris, Milan & Sevilla.
airberlin - Obviously, they fly to Berlin, as well as a lot of other destinations all over the German-speaking countries. They also serve some spots in Spain, such as Palma, as well as Copenhagen, Milan, Amsterdam and Lisbon.
Wizz Air Hungary - The only discount airline I could find that frequently flies to Eastern Europe: Bucharest, Transylvania, Sofia and also Milan.
Air Europa - They fly to a few vacation spots within Spain, as well as Paris.
EasyJet - I’m really disappointed with EasyJet’s presence in Valencia — they only serve London & Bristol.
Lagunair - Two spots in Spain: León and Valladolid.
Transavia - Just Amsterdam.
TUIfly - Only flies directly to Germany (Memmingen, Stuttgart, Köln/Bonn and Hannover). Maybe worth looking into booking a connecting flight from Köln/Bonn since from there they fly to most destinations in Europe.