This material let's you turn on and off a neon sign. This one can be created using curves, a vertex mesh with skin modifier and subsurf, or text object converted or not to curves, or grease pencil layer converted to curves (this last solution is really cool).

Try the different parameters of the material group node to see their effects, but you should not have to move them a lot...

The render is much better if you use the OCIO set for blender from Troy. It is all explained here :
http://blender.stackexchange.com/questions/46825/render-with-a-wider-dynamic-range-in-cycles-to-produce-photorealistic-looking-im