Kelethin would definately be fun. You would have guards guarding the lifts, and above you'd have everything protected from the evil, and if evil was coming up the lifts, you'd be ready to get them, and if possible the women and children can hide at the top
Halas would be cool, because its a one way enter and you have to go across the water into a sort of small opening to the town. You could hide in a lot of places in the town too. Would be an easy to defend because guards at the front of the cave outside of the town could run in and warn you.
Neriak, well.. it's too big for an EQEMu server. But if you were too have like 300 vs 300 players go to war, you'd have people outside the tunnel, inside guarding the gate, people inside the gate, people behind the gate, on top of the gate, and thats just the first part, theres 2 other zones for more people to hide and rape.
Since its a classic server you can't include paineel, but an underground city that requires a key to get too that has a top part that can be guarded from the jungle, the inside on top of the lift, and the outside area which leads to the hole and warrens.
--Edit:--
For the people that voted for freeport, you just made a bad mistake. Why would you want to guard a town that has so many entrances. People from plane of air could sky dive into your town, theres two gates, theres a secret entrance for bad guys. You have a dirty little houses where ninja monkies can hide.
Unless you expect 500 people to guard freeport, your shit in trouble.