3Islands & Spiramp (Updated)

[Nanners]

There are tons out there but Doomsplitter might use a spefic one

There aren't "tonnes" there are 2 main ones and they are Slab6 and VOXED. VOXED comes with your AoS download but Slab6 you have to download.

[LinktersHD]

I think you have forgotten one "Qubicle Constuctor". I think thats the one @Dany0 uses.
-LinktersHD

[DoomSplitter]

Here's the rundown of the tools I used:
1) Photoshop - Overhead graphics
2) Bildramer's Bitmap Converter - Self-Explanatory
3) Pyspades map editor - Cleaning up edges
4) Slab6 - Tree and rock models
5) Voxed - Inserting map models/ making final touches.