It’s been stated by some others already:
The typical locations are France (probably Paris), as for Germany it’s usually Frankfurt. Amsterdam in the Netherlands also has good servers, but I don’t think they are typically used in MMOs. If the focus is West-Europe then I’d suppose the latter two are the better options. If you want to include the Russians as well, then Frankfurt is probably a better option, but I’d imagine it not being significantly different if they connected to Amsterdam either, I don’t know how many people are from the UK or Ireland playing, if their numbers are larger I’d imagine Amsterdam to be a better option.
All-round Frankfurt seems to be located at the centre with good infrastructure. From my personal experience, however, is that a lot of their servers tend to fluctuate in ping quite frequently, something I didn’t notice when connecting to servers in the Netherlands (Amsterdam usually)
