Since it's not costing anything at the moment, you could open up a character slot if you don't have one. Just make a character and get to the world list, you can see how busy each world is at the current moment by the number of chocobos present. I don't think the population fluxes that greatly enough during a day that the server list rearranges that much.

I usually see posts about Besaid or Mysidia otherwise.

And Lindblum is a 2 chocobo world. It was cram packed at launch and locked off from new characters at times, but it has fallen off the highest 1-3 population lists for now.