There is a lot going on in Copenhagen, Denmark is also often ranked as the best country to start a business as the costs of starting one are low (living there is not) see http://www.prosperity.com/entrepreneurship.aspx.
In my country, Holland, many people mention Amsterdam, I don't agree with that in the sense that it is a hub. The up and coming region here is Utrecht, it has a province and university backed business incubator Utrecht Inc. and a government backed gaming incubator, which both enabled some startups with national or global impact. The startup scene is still behind that of other countries and the numbers of 'me too', 'Y for X', 'X for social media' or 'X which doesn't suck' ideas are huge.