Been there before and it was awesome. Lots to check out and most of the stuffs are located at Nangang. If you visit some the other two places, there should be a free shuttle bus that takes you to Nangang. Too bad consumers can only visit on the last day (don't know if they changed it). Visitors must purchase tickets and be over the age of 18, I guess that's due to very expensive products, booth babes, and some male models.
Taipei 101 is a fun place to visit too.