List of Japanese Slang
gkgb (gakugaku buruburu) - To shake with fear. ((((;゜Д゜)))ガクガクブルブル
Kitaaa (キター) - Something shouted when something exciting happens. Literally "It has come."
キタ━━━━(゜∀゜)━━━━ッ!!
ktkr (Kitakore 来たこれ) - Something said when one's hopes come true.
Neta ni maji res ネタニマジレス - Someone responding to a joke post without realizing that it was written as a lie or a joke. ([http://dic.nicovideo.jp/a/%E3%83%8D%E3%82%BF%E3%81%AB%E3%83%9E%E3%82%B8%E3%83%AC%E3%82%B9
Source])
Shoboon ショボーン - Dispirited, dejected. ｼｮﾎﾞｰﾝ(´･ω･`) Source
wktk (Wakuteka) - To anticipate something.
w or any number of wwwwwwww - Basically Japan's equivalent of LOL. Short for Warau 笑, the Japanese word for "laughter".