I miss the little balls you could kick around. Those were so much fun and villagers would even ask for you to get them one. Speaking of which, I miss the fact that you could directly ask the villagers if they want help. And the help wasn't just catching a fish/bug or getting furniture for them; it was delivering/retrieving something or planting flowers around their house.
I miss the tickets Nook would give out when you bought furniture/clothes and you would have a chance at winning that lottery thing at the end of the month.
I also miss washing Gracie's car.
I miss when villagers would walk away from most of your conversations with them with some sort of emotion.
I miss when cranky villagers were actually cranky and when snooty villagers were actually snooty.
I miss when the lazy villagers were like lazy teenagers, not like little kids that are full of energy.
I miss having a villager at the island.
I miss the dump, mainly because I could pick up everything from there and sell it to Nook lol.
I miss signposts being something you can buy from Nook and move around instead of being a Public Works Project.
I miss the fountain.