Classes that need C# wrappers:
Math (Instead of a wrapper create actual C# classes, but which map 1-1 with C++ code so we can move them through C++/C# boundaries):
 -Vector2
 -Vector3
 -Vector4
 -Matrix3
 -Matrix4
 -Quaternion
 -Rect
 -Int2
 -Color

Resources:
 - Mesh
 - Texture
 - Font
 - Material
  - GpuProgram
  - Technique
  - Shader
  - DepthStencil/Blend/Rasterizer/Sampler state

Core objects:
 - RenderTarget
  - RenderWindow
  - RenderTexture
  - MultiRenderTexture
 - SceneObject
 - Component
  - plus specific components Camera, Renderable, maybe others
  - (later ofc ability to derive custom C# components)

GUI:
 - EditorWindow
 - GUIWidget
 - GUILabel/GUIButton/GUIToggle/GUIInputBox/GUITexture...
 - GUILayoutX/GUILayoutY/GUILayoutOptions
 - GUISkin/GUIElementStyle

Systems:
 - Resources
 - Importer
 - Application (startUp/shutDown)
 - Cursor
 - Debug
 - Input
 - Time