Hurr Hurr - is something I always say, or type when there's something fun/exciting going on. (from: QuestionableContent)

Aiiie! - is me, being hyper plus stupid.

Tenchu! plus mandatory grin plus arms flailing - Means that I'm thanking you. Derived from TENCHi mUyo. Don't ask how it got to that.

Doubleplus or Plus - sometimes used as replacement for the word AND.