You're the best.
Kāore i tua atu i a koe.
Good for you/good on you.
Kei runga noa atu koe.
You look beautiful.
Tō ātaahua kē/hoki.
Don't do that yet.
Taihoa tēnā (mahi).
I don't like it when you do that.
Kāore au e pai ki tēnā mahi (āu).