My son has played in the Ga. JUCO conf and Tenn JUCO conf (freshman and sophomore years respectfully) with schools like Young Harris (Ga), Middle Ga, Ga Perimeter, Walters State, Cleveland State, Chattanooga State.
As tough as these teams are, IMO, Florida has the toughest all around conference Ive seen yet. Their year-end Conference championship is unbelievable. I think if you look at the Top 25 rankings anytime during the year you will see maybe up to 6 Florida JUCO's ranked at any given time.
Alabama would probably rank 2nd and very closely behind at that. South Carolina and North Carolina are like Georgia where they usually have 2-3 teams that dominate the rest of the conference year in-year out.