Out of these Animal Crossing games, wich one should I play?

>Wild World
>New Leaf
>New Horizons

>>714593423 (OP)
new leaf has the most to do

>>714593570
So I play that one?

>>714593423 (OP)
New Leaf

>>714593423 (OP)
Let's go to the city

the correct answer is:

wild world

Wild World if you want something close to the GC games. It's basically the original game with new stuff, sanitized dialogue and adapted to the technical limitations of the DS (like living in a smaller with fewer villagers).
Let's Go to the City is just Wild Worlds but at a higher resolution and worse gameplay. The "city" is just a small corridor with buildings that could have been part of the main town without problem, and the sanitized dialogue is more present.
New Leaf is when the main franchise transitioned from comfy town life to chore simulator, but still had enough content available at the beginning to let you chill and take the town's development at a slow pace.
New Horizons is a full town builder simulator that appeals more to people that want to create their own town than to those who want to relax in a comfy place and even feels stressful at times.