Earlier this year The Independent published a list of 50 things which the EU has done for Britain and the Brits. Quite a lot of the benefits are applicable to the cases of other European countries. Here is an excerpt:
1. The end of war between European nations
While rows between England, France and Germany have been a feature of EU summits, war between Europe’s major powers is now unthinkable. The fact that the two world wars that shaped the last century now seem so remote is, in itself, tribute to a visionary project that has permanently changed the landscape. As the EU celebrates the 50th anniversary of the signing of the Treaty of Rome it is clear that while the detailed topography will always be difficult to agree, it is an extraordinary achievement that we are standing on common ground.
7. Crime-busting co-operation, through Europol
This provides a clearing house for EU police forces. The police in EU member states can now use an EU arrest warrant to get suspects moved from one country to another where they will face serious charges without lengthy extradition procedures.
11. No death penalty (incompatible with EU membership)
No EU member state has the death penalty and reintroduction of capital punishment would not be compatible with EU membership. Even countries outside the EU are having to review their policies if they want to be considered for membership of the club, most notably Turkey.
Check out the full list here