Edit: Fixed missing image I'm well aware that you can simply use the FBX Exporter in Unity to do this, however I thought I'd share the settings I've been using to successfully get models from Blender to Unity as I know many people have problems with this. I have this specifically set up to be used only with selected objects because I use a lot of objects and non-deform bones as IK targets and helpers for rigging armatures. These settings result in a scale of 1 and no rotations or scaling on objects. If this doesn't work for you I'm not sure why. You'll find this panel in the Export FBX setting.