Super Smash Bros. Board
The Super Smash Bros. Board is a message board on IGN where people can discuss topics relating to the Super Smash Bros. game series and is essentially the previous incarnation of the GCB. Back in the early days of IGN, when Super Smash Bros. Melee was still relatively new, the board enjoyed a rather sizable community. The community was so large and active at that point, that many felt the Community Thread for off-topic discussion wasn't enough for all the various off-topic subjects that the community wanted to discuss.
It was eventually decided that a new board was needed for the smash community to discuss things other than smash. There were a few different ideas for the name of the new board, but in the end it was called the Games Community Board. After the formation of the GCB, a large ammount of Smash Bros. Board regs took place in The Great Migration and traveled to the GCB. The thread petitioning for the new board (the GCB), can still be found here.
Several of the Super Smash Bros. Board regs started posting on the GCB and eventually stopped posting on the Super Smash Bros. Board altogether. Over the years, the GCB has accrued users from various other boards becides the Super Smash Bros. Board, most notably the Legend of Zelda Board.