Somebody in the thread mentioned Jackpot, which for a while I actually thought would make for a good revival on like The Hub(same with Chain Reaction, even though GSN already revived that).
Another idea I had for a Hub revival, but I guess it could work with in a GSN revival as well is Bumper Stumpers; only problem with that is you would have to tweak gameplay since the show straddled games.
Somebody also mentioned Crosswits in this thread, which I thought would be good for a revival(with some tweaks in gameplay; of course this would have been great prior to Merv Griffin's Crosswords airing, not so much now).
With some tweaks in gameplay, and payoffs maybe Trump Card would make for a good revival. On that same vein, if GSN still had the people running it that green lighted Friend or Foe, Whammy, and Russian Roulette, I thought Split Second would have made for a good revival as well.
Actually, I came up with a revised payout structure a while back for the show which would have had contestants winning somewhere in the neighborhood of 4-5,000 dollars per show, possibly more depending on how many questions each player answers(which i'm sure GSN wouldn't have a problem with budget wise).
Speaking of that Split Second revival idea, and the revised payoffs I was thinking something along the lines of this:
In Round 1 of the main game, three players getting a question right would be worth $100 to each of them, two players getting a question right would be worth $250 bucks to each, and one person getting a question right would be worth $500.
In Round 2 of the main game, the payoffs would be increased to $500 for three players getting a question right, two players getting a question right would be worth $750, and one player getting a question right would be worth $1,000.
The Countdown round would stay the same, and maybe you could add a bonus game of some kind as well.