I've actually never seen "Eye Guess" enough to judge. My vote is "Chain Reaction", closely followed by "Go". Both have great playalong value, and could make for a great party game.
Chain Reaction was a good format, and despite it having a longer run WITHOUT celebs, I still found non-celeb Chain Reaction quite dull, despite Geoff Edwards' attempts. Edwards' version also had a better scoring system. However, Cullen's version definitely had a more compelling bonus round (despite many changes in the payoffs and time allotted).
Go was, at times, fun to watch, but not everyday for a full half hour. I mean, "How...long...can...you...watch...people...talk...one...word...at...a...time...before...you...go...insane?" Playalong? Well, if you're watching with a couple of people, one not looking at the screen, that could work, but it would be hard to play along watching alone. I give Kevin O'Connell props for being a very competent host for his first and only hosting job, but this was not really amongst Bob Stewart's best shows.
I would agree with you on Eye Guess. Bill Cullen was the perfect host and I wish there were more Eye Guess shows out there. I also believe Eye Guess could've worked with other established hosts because its format was very solid and simple. Dick Clark, Geoff Edwards, Art James (he hosted a very similar game called Matches and Mates)and maybe Richard Dawson could've handled Eye Guess if Cullen wasn't available.
Jackpot!, IMO, could've had potential for a longer run if NBC hadn't decided to tinker with it by dropping the riddles in favor of trivia questions. When you have a game show with 16 contestants, how can you make each one stand out and not make them seem like people just getting face time? How well did we really know the contestants in 1 vs. 100 or Winning Lines? Not very well, because they didn't play for 5 days. Geoff was very good at keeping tabs on all 16 players and giving the viewing audience a reason to root for them. Jackpot's format was perfect for a game of riddles, and Bob Stewart should've NEVER tinkered with it by doing a celebs vs. civilians format called The Riddlers... David Letterman did a fantastic job with a very weak format, but when you have celebs that don't seem to care much for the game (Michael Mc.Kean saying "let's get this overwith" didn't help much) you're in trouble.