Which public lots are the best for tailgating at a Cincinnati Bengals Game?

Dec 2011
We are going to the 1/1/12 game and want to park in a tailgate lot by the stadium. Unfortunately we are not season ticket holders so we do not have county lot passes. We are a large group and want to have our own tailgate. Which public lot/lots are the best for a solid tailgate? and what time do the lots recommended generally fill up by?