I have spent many a frustrating hour working through some of the querks that come along with Unity3D. In particular, making Blender models work was something I had to figure out through trial and error because I could not find it online anywhere. The following Image shows the way you need to orient your model in blender to have the Z or Vector3.Forward in Unity work.

After the model is in this orientation in blender, Press "N" to show the transform panel. In the interface that shows up you will see the "Rotation" section. Set all the values to "0" and hit "CTRL+A" to apply the rotation. After that, you can save the .blend file and drop it straight into Unity3D. The Z vector will then be forward on the model, and your whole life will be better.
Leave a comment if this helped. Good luck.