I choose FEI, Atamara, and Dwilight.
FEI because I think there is a fantastic diversity of cultures and realms paired with players that genuinely make the game interesting.
Atamara because, while I don't care to play there anymore, I think there is potential for something interesting there.
Dwilight because, while it hasnt always worked for me, the sheer diversity and opportunities that could be had there seem to be worth holding onto. Plus it works nicely for a testing island.