Things I've said:

"I totally agree with you! Enjoying the pond (not that it's going anywhere) is a much better thing to do than improving life on the island!!" *notice the sarcasm

"HURRY UP AND BECOME A MASTER AND STOP DOING LAUNDRY!! "

I have said this to all my villagers at some point: (except George of course) "Why can't you be more like George???????"
*George is my best villager because he Dislikes Laundry(OH HAPPY DAY!), which resulted in him becoming a Master in 2 skills (Scientist and Builder) in the same day!

"OH NO! Not another red-head kid!"

"That's it! No more babies for you!"

"And what do you think you are doing?"

"...But, you just ate! You can't be hungry again! Get back to work!"

"Hurry up and drop your kid already, we need you!"

"Not another mushroom!" *Upon picking up my 164th mushroom after just 2 days of playing*

"Don't even think about touching those coconuts!"

"You couldn't reach the coconuts the last 5 times you tried! What makes you think you'll reach them now??"

"Hurry up and show up, you dumb (uncommon/rare) collectable!"

"Where did all those kids go? They were here just a second ago!"

"Not one of you likes to run??!!"

"Who in their right mind dislikes butterflies?"

"You don't like fish? Well, FYI, that's all you'll be living on for the next year!"

"Please, please, please, let there be an Island Event!"

"Wellll??? What are you waiting for? TURN 14/18 ALREADY!!!"
I've said soooo much more, but I can't remember! lol