most of the time in all PvE i run my A/R assassins promise/lightening reflex build. it uses all faction skills if i remember right and is highly affective with great dmg. if u want help and a walk through of diffrent build i use for PvE and PvP contact me in game.
most of my PvP builds are centered around heavy dmg spike, such as shadow prison varients, mobious, and i also run 1 palm strike build occassionally, also with the right team build there is a nice locust fury/splinter build, with a degen necro, air spike ele, and shutdown mesmer that my guild runs.