Hmm.. If I can remember some.. めちゃめちゃ(Mecha mecha) - Quite, very much.. ex 彼女はめちゃめちゃ可愛いかな。- Kanojo wa mecha mecha kawaii ka na (She is quite cute, isn't it?) ぶっちゃけ　(Buuchake) - Honestly, to be honest.. ex ぶっちゃけ、この映画はへんだよ。 (Honestly, this movie is bad) おひさ　(It's been a while since...) It is like 久しぶり　(hisashiburi) ex おえ、おひさね。 (Hey, it's been a while. [since I last saw you]) さいこだわ (Saiko dawa) - Its awesome それは君の新しい車の。さいこだわ。 (That your new car? It is awesome.) Note> The "dawa" makes the sentence a bit feminine. きもい (kimoi) - Creepy, gross.. Usually used to describre stalkers, perverts.. ex あの男人はきもいだよ。 (That guy is gross/a creepy) やばい (yabai) - It can means "bad" or "good" depending on the context.. ex やばい、もう遅刻だ。(Yabai! Mou chikoku da.) Damm it! I'm already late! やべえはーこのバンド。(Yabee wa - kono bando) (Wow! This band is awesome/nice) Note> Yabee is a vatiation of Yabai, but it's the same. All the sentences are very informal, of course. So be careful when speaking.

やばい。It's kind of like the slang "sick" in english. Literally it has a negative meaning but in slang it can mean really cool or something similar to that. for example: このまんがはやばいよ。ちゅうどくせいすぎる。＝　This manga is dangerous. It is too addictive.