Id hafta say the first screenie is the best. Its not too cluttered and you made good use of the different sized mushrooms and fog.
Screenie 2 looks a little empty. Theres not much tile or ground variation. The main focus is kinda plain and theres not really much to look at.
Screenie 3 Looks pretty good but its a little cluttered with short doodads. Also, the angle isnt very epic.
Screenie 4 looks pretty decent but the over use of doodads with the same height makes it look cluttered. Also, the ice just kinda ends which seems unrealistic.
I would suggest removing the green spiderwebs in screenie 5, they look out of place. If your going to use them i would tint them a light blue using the object editor and make them a little larger. The use of many small doodads ususally looks alot worse than using one big one.
The last screenie looks pretty decent but it could use some more shrubs and rocks and tile variation. The sky doesnt fit with the northerend theme either.
Some tips, use the terrain raise tool and create some more hills/plateaus on your terrains and it should help out. Also theres no water in any screenshots (personally I think the water is one of the best looking things in all of WC) Also, before you take screenshots, make sure you have AA (anti alias) on. You can turn it on under preferences in the WE.