Press Your Luck, The $25,000 Pyramid, and Scrabble towards the end of the block circa 1993-95.
Those were good shows, but especially in the case of 1994-95, you had the lousy originals Quicksilver and Free 4 All, as well as a shortened lineup. GSN launched in December of '94, but most people continued to watch USA until their game show block was purged, before moving onto the Family Channel (FAM).
When the block first started in 1984, the only shows were Candid Camera and the Gong Show, the former not really a game show to many. Make Me Laugh also was around, but aired late in the evening. CBN (pre-FAM) was the place to be in those early days, with Blockbusters, Face The Music, Tic Tac Dough, Card Sharks, and Hot Potato forming their lineup around the fall of '84. Then in the spring of 1985, the Joker's Wild and Bullseye were added to USA's afternoon game show block, effectively beginning a decade of secondhand game show fare that would allow many fans to catch them after school that they missed the first time around depending on when the original shows were scheduled in their market, or if they were even carried at all. It aired around the same time as CBN's block, and likely due to this, a fair number of VCR recordings from this era, especially by a recorder who lived in the Bay Area, survive today.
On September 30, 1985, the USA block expanded to three hours, with their first original, the all-new Jackpot, along with Kennedy Chain Reaction reruns, which soon became relaunched the following summer as an original, while Candid Camera got the boot. By then, CBN's block had shortened to 90 minutes, including what would later resurface after a stint on USA: Jim Lange's Name That Tune. A year later in the fall of 1986, the block had shifted an hour earlier (2-5 PM ET instead of 3-6 PM ET), with the Gong Show being moved to the morning and All-Star Blitz and Liar's Club joining the lineup, the later replacing Make Me Laugh. By then, CBN had jettisoned its game shows with the exception of Tic Tac Dough around midday (which would be dropped by the end of the year), and wouldn't return with a block until 1993 when Trivial Pursuit launched, by this time as FAM. Anything But Money would then join the Gong Show in its mini-morning block around this time. Let's Make A Deal (1984-86) would expand the afternoon block even more to 3 1/2 hours when it was added late in 1986. But around this time, the Joker's Wild was dropped for Love Me, Love Me Not, a rather bizarre relationship show.
The summer of 1987 added Play The Percentages and Hot Potato, along with the premiere of another Canadian-produced original: Bumper Stumpers. Liar's Club and Love Me, Love Me Not would be replaced by Press Your Luck that fall, by which time the block had taken nearly the entire afternoon at 4 1/2 hours, starting with Anything For Money at 12:30 ET, followed by the Gong Show, LMAD, Hot Potato, PYL, PT%, Jackpot!, Bumper Stumpers, and Chain Reaction. A few months later, TTD would replace The Gong Show.
The fall of 1988 would add High Rollers (Wink) and the long-forgotten Check It Out! replacing Anything For Money, making the block a full five hours. By the end of the year, the $25,000 Pyramid would replace the short-lived Check It Out. The block finally seemed to reach its full potential, and combined with NBC/CBS's morning game shows, early evening syndies like Wheel and Jeopardy!, and a few graveyard/late night ones like The Gong Show '88 and Love Connection, most of the day had the ability to watch a game show at some point, unmatched until GSN's launch six years later.
Over the next several years, we'd see Face The Music, Scrabble, Couch Potatoes, Davidson Hollywood Squares, Wipeout, Win, Lose or Draw, the $100,000 Pyramid, the 1990 versions of TTD and TJW, Talkabout, Sale of the Century, and finally, Casesar's Challenge join their schedule. The block would gradually dwindle in terms of time, being cut to a still large 4 1/2 hours in the fall of 1990, four in the spring of 1991, three in the fall of '91, back up to four in spring 1993, and then back down to 3 1/2 in early 1994. But it was still a great place to go for the game show fan. Unfortunately, on November 14, 1994, the block was once again shortened two just two hours: $100K Pyramid, Quicksilver, PYL, and Scrabble, surrounded by reruns of drama/action shows that the network was increasingly embracing. February 4, 1995 would see another purge with Scrabble and PYL dropped, leaving just $100K Pyramid and Quicksilver. Game shows on USA were truly on life support after $100K was siphoned off a month later, and although the block made a mini-comeback with $100K Pyramid and Scrabble/PYL rejoining shortly afterwards, little did we know that October 13, 1995 would be the last time that we would be seeing the later two on the schedule, with $100K Pyramid being replaced with a second Scrabble episode shortly beforehand. USA replaced those with Love Connection reruns the following Monday. Those eventually became part of the USA Live block the following spring, but it was clear that the channel was not known as a place for games, and around the same time, the Cartoon Express block was dropped, and USA became just a drama/wrestling channel that I wouldn't watch again. I temporarily moved to FAM for the next couple years until my cable provider got GSN in 1997.
I'd still say that the period from when PYL was launched in 1987 until $ale was dropped in 1994 was the best time for watching USA, and I watched the second half of or so of that period growing up.
Another thing about classic USA is Dance Party USA, which in away was a lot like what the old American Bandstand was, and that followed the game show block for several years.