Last I knew, Freeport was the most populated server, followed by Antonia Bayle and Crushbone (I think). I too am thinking about starting it up again and making a new character (I have a 90 Necromancer on Antonia Bayle and Freeport servers).
I play evenings PST and Freeport seems to be the most populated server most nights of the week. If you decide to pick it send me a tell, char name: Daene (or Sniik if playing with Fiance)