Tough one.
Get together has my favourite world and adds more community lots and has some fun objects like darts, table football, don’t tell the llama. That being I don’t play with clubs but I don’t feel I’m missing out. Seasons helps a ton for immersion and it can throw a spanner in the works in terms of activities being rained out for example. I really wouldn’t like to play without it.
Seasons has a few nice activities. If I were you I would pick seasons as Get together will go on sale before seasons will.