The NES has one of the most prolific unlicensed libraries ever. Not including pirates or repros, what are your favorite unlicensed NES games? My top 10, not entirely sure of order:
Spiritual Warfare
Bible Adventures
RBI Baseball 3
Operation Secret Storm (it makes me laugh, and Saddam's wearing a tag that says "DICKtator")
Quattro Adventure
Ultimate Stuntman
Fantastic Adventures of Dizzy
Exodus
Super Sprint
Vindicators
I didn't include Gauntlet because it had a licensed re-release, as did the first RBI.