After adding all the sets on Reply #6 on up, I've found that this list has 13 sets of 5 and 15 sets of 6.
Between 5 and 6 seems to be the average number for most-parodied product sets at this time. Originally, it was between 4 and 5.
And, as mentioned above on Reply #21, Wacky Packages has the highest number of releases with 24 (although Cap'n Crunch, Bazooka, Tootsie Roll, Reese's, Planters, Snickers, Pepsi-Cola, Kit Kat, Butterfinger, Dunkin' Donuts, Kool-Aid, Hot Wheels, Raisin Bran, Frosted Flakes, Play-Doh, 3 Musketeers, Milky Way, Garbage Pail Kids, Charms, Crest, Mr. Clean and LEGO are all slowly but surely catching up to it with 22, 21, 14, 14, 14, 13, 13, 13, 12, 12, 12, 12, 12, 11, 11, 11, 10, 10, 10, 10, 10, 10, and 10, respectively). Also, as mentioned above on Reply #37, Gadzooka Bubble Gum is the most individually released Wacky of all with 28 (including one that was unreleased).
Always remember, though, that all of these figures are both subject and more than likely to change at any time, of course.