What are some conductive filaments that can be used in printing electronics?
At this point conductive filaments are a very new thing. All the filiments on the market are PLA based that have been infused with Carbon or Graphine

However I worry you over estimate what you can do with this. You will at most be able to 3d print a simple wire and power a LED. You will not be able to run a microcontroller, and honestly I would expect a complicated print to have too much or too little resistance, maybe burst into flames.



You really should look into the Voxle 8 and other printers. The printer is really the driving factor. Using a conductive filament will not be enough. Note this printer uses a syringe not PLA plastic.

Here is a Voxle8 print.