hehe thanks for comment guys;D best in the sense of how big the defense is;) many best way of doing it for sure;) hehe

definitely not the best, rather close to worst xd

Cute, but a waste of resources, and can't stand a troll attack. Raise the ground, as previous poster said. (Then you can put your walls and stuff behind if you want.
A defence is no good if it can't resist trolls.

Sorry, but waste of time and rescources, best defense is digging a trench and make the water acces point steep enough so nothing can climb it.
Looks nice tought.