Dejavu is an excellent large scale mature guild that is growing by the day. We are nearing 300 members so that no matter what timezone you play there is always someone online to keep you company.
A membership of this size has made it very easy for me to find people available to quest, WvW or help out with an unusually difficult story quest. Another benefit is that we have many level 400 crafters.
Dejavu has a Vent server and a very nice guild website. To join all I had to do was fill out the application at www.dejavublood.com.