Shoryuken
The initials(and the actual command notation as well) for the most infamous move in fighting game history, shoryuken.com has become the central community for up-to-date fighting game info. Although they are very much Capcom oriented, you will find tons of information about various fighting games and the competitions that take place within the fighting game community.
Orochanagi
Orochanagi is the longest running community for SNK related fighting games.
Virtuafighter.com
As you might have guessed, VFDC is your one stop shop for Virtuafighter info.
TestYourMight
If you’ve ever played Mortal Kombat, then you know all to well about this famous quote. Testyourmight.com covers the newest MK in the franchise as well as other fighting games developed by Nether Realm Studios.
Dustloop
Dustloop is a community for the Arc System Works fanatic offering plenty of information on all the popular fighting games the developer has to offer such as Guilty Gear and Blazblue.
Melty Bread
If your looking to get information on Under Night In-Birth or looking for an active Melty Blood community, Melty Bread is definitely the place to go.
Tekken Zaibatsu
Popular community for Tekken players.
Skull Girls community.
Homing Cancel is a community for the EXAMU fans creators of Arcana Heart 3 and Aquapazza.
Dreamcancel is another community for SNK lovers. They host some great bi-weekly online sessions for The King Of Fighters games on steam and even recently the new KOFXIV title!!
It probably can be said with out a doubt that smash brothers is one of the strongest fighting game communities out there and with the new Smash coming sometime this year you may want to join in preparation.
Event Hubs is your one stop shop for stats for some of your favorite fighting games. You can vote on characters that you feel are the strongest creating a tier list made by the community. They also give you update information for fighting games and competitions as well.
DOA World is a site dedicated to fans of the Dead or Alive franchise.
Free Step Dodge
Free Step Dodge is another community for Dead or Alive fans.
ST Revival is home to the legendary Super Street Fighter II Turbo. ST Revival has tons of information on SSF2T and even holds annual tournaments online.
Anther’s Ladder is a Smash Bros Community whose main focus is online play for the different Smash Games available. There is a player ranking system for each Smash game and there is also an area to submit online tournaments to participate in.
TekkenGamer *New*
As the name ascribes, TekkenGamer is an all new community site for Tekken fans. At the moment you will find resources for both Tekken 7 and Tekken Tag 2 Tournament.