Greg Costikyan's SPI Compendium http://www.crossover.com/costik/spicom/design.html lists 96 titles by Dunnigan at SPI. I know he did a handful of titles for Avalon Hill before SPI (including PanzerLeader, PanzerBlitz, Outdoor Survival, and Origins of World War II) and a small number of titles after SPI, including Hundred Year's War. My guess is that his total is in the range of 110.

Sid has at least 135 distinct published titles; I've seen statements that the total is actually closer to 200, but the best list I've seen is around 135, and I know that there are a few titles not on that list, including anonymously designed games for Parker Brothers.

This includes Sackson's collections of games (Gamut of Games and the Beyond series of books--30 games in five volumes), but only the Sackson games from those collections.

But on the other hand, the Dunnigan list includes games which I know he didn't actually design, like The Plot to Assassinate Hitler--which was actually designed by its "developer" and developed by one of its "playtesters", working from a Dunnigan design model. But Dunnigan still designed a staggeringly large number of games for SPI in a relatively short time, including several of SPI's classics.

I believe Reiner has not yet broken 100 titles, but at his current rate, it won't be long. According to the list at http://194.168.54.52/chris.law son/rk/index.htm, Reiner has around 60 commercially published games--but one of those is New Games in Old Rome, which is 14 separate games; also, this list does not count his games for Games and Puzzles magazine, of which there were 16 (at least some of which have been republished commercially), nor the separate games in his book Games for Dice and Cards, many of which I suspect have been published commercially.