I am of course biased on the type of community threads I go into, but I love the Guild Wars 2 community here on GAF. Particularly based on what the players have accomplished. The devs have given shoutouts to the community thread, some of the groups members have made tools and guides that help many players, and inside the game, GAF guild helps other guilds who is failing missions.
Every saturday evening we do casual guild missions together. We have tons of beginners who come with us and no man, charr, sylvari, norn or asura are left behind as we go through insane guild jumping puzzles, or fight over vast numbers of other players in World vs World mass server PvP.
GAF guild is also a very diverse guild with people doing different things in the game. Some are dedicated to the PvE, some to the dungeons, some to the fractals, others are all-arounders, some pop in and out with some hiatuses due to real life.
They've done really good. Some have made outside the game tools like controller support (the best config I've seen), guides that are appreciated on other sites!