Quite a few people have indeed already mentioned regions that wish to become independent from their current internationally recognised mother-country.
Besides the common suspects (Catalonia (Spain); Flanders (Belgium); Frisia (The Netherlands); Scotland (UK); Basque (Spain/France); Bavaria (Germany); Corsica (France);...) - There is also Székely Land in Romania, and of course in Ukraine, you have Donetsk.
What is interesting however is the creation of the Committee of Regions, a body of the European Union that allows these regions to be heard and have their own political influence. In its footsteps, various organisations working together with these regions have sprung up (AER or Fedra for example).
All these regions that have very definite identities make use of this portal to work from their respective regions. Some even have said - or least voiced their hope - that Europe is growing towards a federation of regions.
The problem is that with a continent were history has spilled so much blood, and contemporary history has abused identities (whether it be religious, linguistic, ethnicity, culture, or simply aesthetic (the colour of your skin)) so often, it will be decades before people can see past these divides (if ever).