Saw this and we get it quite a lot lately xD
Mostly from sissy_lucas.
Anyway, gg is also kinda dumb and lost all it's meaning at this point, since ppl throw it always, even when their team just stomped/got stomped by others with no actual competition.
Schizazoid I didn't wanted to mention name.. but yes your right ! xD
GG stands for good game or great game.. I think it's pretty fair..