FYI I reposted the GSN Y2Play finales marathon from December 31st, 1999. Eight hours of final episodes, covering quite a few of the series mentioned in this
Although there were a few entries left in the medium, the end of Super Password doesn't just feel like the end of the series, it feels like a broader finale for the glory days of daytime games as a whole. NBC daytime would never feature more than two hours of daytime games again after that day. It's an episode that revels in it's own emotion. The hilarity of turning the contestant plug into a Help Wanted ad for the staff. Reserving part of the closing remarks for Betty. Bert's clear sadness at not being paired up with Gene Wood anymore, at least here (or with all the other staff-turned-recurring characters). The joy of giving the $10K bonus away on the last attempt. It does every other gameplay and emotional beat the others does well, at the same time. And in many ways with hindsight, it feels like a swan song for daytime games in general, who outside of Price now have less than a half decade left at that point and many of the remaining series are short-lived shows largely left on the shelf historically.
CBS What's My Line is almost assuredly my silver medalist. Much like Super Password above, it's something of a swan song. The show had been on the air for basically the entire meaningful history of network broadcast television. It represented the shift away from live or as-live programming in favor of pre-taped scripted series. It was the end of panel shows in prime time, and the end of game shows as a credible vehicle for A-list celebrity appearances. The Daly Mystery Guest segment is delightful, and while Goodson was known for making appearances on shows, Bill Todman most assuredly wasn't - so Line's network exit being meaningful enough to get him out of the office? Is a statement. And it's just a great half hour of TV.
Somewhere in between the two is ABC Split Second. The show itself and for most of the core game is no-nonsense, only to turn on it's side near the end. Just giving the contestant the car. The sincerity in both Tom and Monty (and Jack Clark and Jay Stewart). Monty has always struck me as having a certain reluctance to ever acknowledge on-air the degree to which he's "the man behind the curtain" on his shows (there's a difference between saying a show is a "Hatos-Hall Production" and outright going "Yes, Monty is the actual boss of everything around here.") but here he does it. Here too, the world was changing. The finale comes in the midst of a two year period of massive changes at ABC and in daytime as a whole. It's a damn shame that this show is almost completely lost outside of a handful of home recordings (and at least one master)
Honorable mentions: Dawson Feud (ABC '85), Newlywed Game (ABC '74), Sale of the Century (NBC '89), Now You See It (CBS '89).