The recent NL PC thread was one of the more informative ones but I would have to go with the post on Canadian Post cereal cards in the postwar forum. Absolutely fascinating stuff, far more facets than I thought the issues ever posed.
http://www.net54baseball.com/showthr...ighlight=maris
If it isn't too mean for the holidays to say it I also liked the November Mastro smackdown thread.