Choosing EU server
Take a look at https://leaderboards.guildwars2.com/en/eu and the WvW board. Choose according to how you want to play WvW. If WvW does not matter any server is fine.
See if any of the servers have community websites/forums and join up to ask what it’s like on there for WvW. As Garambola said, if you don’t WvW then it doesn’t matter because Megaserver.
Keep in mind FoW, Vabbi and RoS are all lowest tier in WvW – meaning simply they have less people in that format. With the dawn of megaservers in PvE, it doesn’t really matter for this side of the game, but if you tend to play WvW you’ll likely prefer GH – take a peek at http://gunnars-hold.eu
Unless, that is, you want the maps to be half-empty most of the time so that small-scale roaming is more impactful.