Episode 4, by no contest. I, myself, actually played episode four FIRST, because it was the higher rated on
http://www.gamingw.com and thought it was a overall great game. I was surprised that a game made on a primitive program like RPG Maker 2000, a program that only took me a day to learn, could be such an achievement. Anyways, ep4 is the best because of Estrana, and lun made great use of "extras" (You know, the npvs, that arn't part of the story[random guys on street])
I hope that in ep6 there is a few minigames that are good.