Every ARTCC also seems to have a different atmosphere to them. Their social culture and how seriously they take this hobby. It helps to list out what it is that you are looking for in an ARTCC and then maybe people can help guide you from there.
ZLC for example:
We try to get our procedures and training as close to real world as possible without you having to study for 40hrs a week.
Our social atmosphere is hit or miss... we sometimes have 6+ people in our discord talking about the newest video game, aircraft, CPU and sometimes we sit there and debate the finer points of point-out procedures.
Then other times, you can be the lone wolf controlling.
We go for quality rather than quantity.
There are many ARTCCs that share this same outlook and then there are others that hold the complete opposite atmosphere. Good luck on your find!