Guild Wars 2

1. Which server has the most Greek Players?
2. Can I join a guild on another server?
3. Is there any way to change server for free?

1. I don’t know. In the PvE world we all share the zones from all servers. Mega server.
http://wiki.guildwars2.com/wiki/Megaserver#Megaserver_system
2. Yes, but you can’t play with them in WvW, just PvE & spvp.
3. Not often, or the one you want.
“Periodically, ArenaNet will offer incentives for players to transfer to lower population worlds, including waiving transfer costs.
During WvW tournaments, Arenanet will change the pricing to encourage movement to lower-ranked servers and discourage people from transferring to better-ranked servers just for the tournament rewards.”
http://wiki.guildwars2.com/wiki/Transfer#Transferring

If you delete all your characters you can choose a new server for free. This is a better option for new players, deposit anything you have into your account bank first if you choose to do this.

1) the game has Megaservers now. All the PvE servers are together on the maps. Which server you are on only matters for WvW.
2) “Guild membership is not limited to a single world — a guild can have members from any server, whether in the US or EU.” http://wiki.guildwars2.com/wiki/Guild
The important distinctions are though, you can’t play with people on a different data center (EU/NA) and you can’t WvW with people from other than your server.
3) free transfers: http://wiki.guildwars2.com/wiki/World#Transferring
“Accounts without active characters
The transfer fee is waived for accounts without any active characters. This allows players just starting out to change to another world that is not full. You also can transfer without cost if you delete all your existing characters. The next time you log on without any characters, you will be prompted to choose a new home world.

Please be aware of the following:
A) Transfers to any game world — whether free or paid for with gems — are allowed only if the population of the world is at less than capacity.
B) Transfers to any game world — whether free or paid for with gems — are allowed only once per seven days.
C) If you decide to delete the characters on your account, Customer Support cannot restore them, in whole or in part.
D) Items left on the characters will be deleted and cannot be restored. Move items to your personal account bank to preserve them."

ZeusDX.6813:

1. Which server has the most Greek Players?
2. Can I join a guild on another server?
3. Is there any way to change server for free?

1. I’ll chance a guess at Aurora Glade, based on the fact that the guild I’m with Dragon Season (DS), has a majority of Greek players. Come join us, we’re international too with people from all over Europe. Send me a PM in-game and I’ll forward it to one of our (Greek) officers.
2. Yes you can, but if they’re on a different server than you you won’t be able to do WvW with them.
3. Sometimes during WvW season breaks, Anet offer them up for free.