I use maya for all my modeling. But since I dont have it on my laptop, I use wings. Its very frustrating at times but at least its 3d.
I have tried Zbrush and didn't really like the "original interface". Im waiting for mudbox to come out, hopefully soon. I havn't tried silo, but hexagon looks cool.
Nothing can touch maya, I find, in modeling.
Imagination is more important than knowledge.