If you have your own original NES controller, I would suggest using the "NES RetroPort. I have had one for over 5 years now and it works like a charm every time. No lag, no setup issues, no problems connecting to ANY device with a USB. Here is the web link: http://www.retrousb.com/product_info.php?cPath=21&products_id=28
Trust me, you won't regret this decision EVER.