"PDQ" ran four years in syndication (and NBC O&Os), but lack of subsequent availability has limited the scope of discussion in later years. Same for "It's Your Bet," another relatively long-running syndicated entry. Think all I've seen is a fall 1969 episode (w/Lyle Waggoner, Imogene Coca and partners) and the prank between Burt Reynolds and Tom Kennedy.
For the first run of "Pay Cards" we have the episode with Celeste Holm, and many people seem to like or remember "Super Pay Cards," but in the interim, there was a 1973-75 series on CTV hosted by Paul Hanover that's much more obscure.
The daytime "Do You Trust Your Wife?"/"Who Do You Trust" had a lengthy run of six years and three months (1957-63) and the name cachet of Johnny Carson for its first five years, but not many episodes seem to be available.
The same could be said of many early shows: "Who Said That?" (1948-55), "Twenty Questions" (1949-55), "Down You Go" (1951-56) et al. The latter is described as something really special in Brooks and Marsh's book on primetime TV. The one surviving episode (which admittedly is from the post-DuMont period) seemed to me OK but not overly noteworthy.