If you don't need english speaking community - go for MYSRO.
It's not crowded,it got normal updates(like SWSRO,ZSZC) and most likely it doesn't lag.
No events.
Pay2Play - 2$ each account.
If you want english speaking community and servers being always full - go for ZSZC Fire/Water or "vip" server with 80cap - ZSZC retro.
It's 24/7 crowded,50% of english speaking players and rest is foreign. Events are being made quite often.
Fire/Water - Free.
Retro - 10$/account.
I suggest you not playing at SWSRO2 - it's corrupted as hell,GM is pathetic and corrupted as well. 80% of the server is turkish community which will go 5v1 on you then flame you after you die that you are noob and so on. If you kill one of them,you can as well say goodbye to your account as they will cry to Tombalaci(freshly promoted GM I talked about) and your account will get hacked after that.
SWSRO1/SWSRO2 - 5$ each account.
Last server I suggest is SJSRO,it's still 90 cap,has no updates,GM doesn't do anything at this server. No events,no nothing.
Free account,but register is mainly offline.
Neither. Play rsro or csro.