Undergraduate European Computer Science Schools and their application process?
If you believe in university rankings here is the one from QS. According to it, the following nine European universities belong to the world top 50 in Computer Science: Cambridge (UK), Oxford (UK), ETH Zurich (CH), Imperial College London (UK), Ecole Polytechnique Fédérale de Lausanne (CH), École Normale Supérieure, Paris (FR), University of Basel (CH), University of Amsterdam (NL), London School of Economics and Political Science (LSE) (UK). Basically, I would say that all universities in the world top 200 list are good. 

Moreover, depending on what are in Computer Science you prefer, it might be a good decision a university outside of this top 50/200 if they are specialised in the area you like.