Quote Originally Posted by Tranquil View Post
If I recall correctly, Phoenix is the most populous server all-around. (Phoenix being an EU-server).

A check at XIV Soul shows that it is indeed the most populous server all-around, with Exodus being the most populous US-server and Kujata being the most populous JP-server.

However, I am not sure how reliable this data is, as it seems to base its numbers on Lodestone alone and as far as I know, inactive accounts don't get purged (?), so it will not show the current relevant subs per server, but it's interesting data nonetheless.
XIV Soul should never be used as a source.

OP, you want to see which servers are most active? Just take a look at which ones are not available to transfer to during most of the day. It's those.
You'd have to get up in the wee hours of the morning to transfer to them, however.