An organized one with a real purpose. Not just PKing or no point at all. The most powerful guild in Graal gets about 7 members on one server at a time, and you can't do anything with only that amount. It would be awesome if Graal had a guild system where there were only 5 guilds, each with a specific purpose, customs, etc. They could each have a guild house which would have stores and stuff that only guild members could access, but it would cost money to maintain and build the stores. (How would the guild pay for that? An NPC based guild treasury
)
But right now, I'm guildless. It's pointless to be in a Graalian guild, people.