The following came to mind the most readily, I'm sure there are one or two more examples:
"Rascals" and its sheer idiocy of plotting contrivances to get the Big-E, combined with some of the worst dialogue in Star Drek, such as "take the adults to the transporter room" since this episode revolves around the heroes turning into kids.



That said, the casting of the kids was pretty great and the Ro/Guinan subplot works overtime to keep this story from being sub-season 1 in quality.
The basic plotting that Riker almost gets Starfleet Command (and Academy) taken over thanks to a game, brought in by someone on TNG's STD planet (no relation to Wrigley's Pleasure Planet, of course.)
Wesley putting together a kit for a portable tractor beam for some reason, then reversing a diode or whatever, and grins to everyone how he invented a repulsor beam. You know, the one that saves the story in just the perfect nickarooney of time. (actually, 70% of "The Naked Now" is a cringefest where one might have to be drunk, and at the tail-end of puberty, to begin to enjoy this one...) That said, at least LaForge and Yar get what approaches character development, even if it's low-hanging fruit.
Also in the same story, Wesley creates not a voice synthesizer, but a tape recorder that records voice clips and edits them into phrases without sounding like "Kirk On Meth". That one was ripe for heckling when "Futurama" aimed right at it with Cubert pulling the same shtick but to greater effect... but I digress.
But in all fairness, Season 1 is so easy to pick that it's almost undeserving since the show was at least trying different formats and finding its feet as best it could. So let's go to the other low-hanging fruit at the other end of the show's run, just to get that over with:
Sub Rosa.
Yup. The whole thing is one big glob of cringe. Like when you have a really bad sinus infection and you sneeze, but you miss with the hanky and a lot of it is still dripping off the edge of the nose? Yep. That.
The fact that "Booby Trap" has just enough vagueness in the dialogue that the story allows the viewer to perceive Geordi creating a virtual sex doll (when the computer created the
personality, with that 9.37% margin of error and Geordi forgets about that little tidbit... among other issues...)
And, of course, "Galaxy's Child" where, even under the best-case scenario, there's one scene where Geordi demands she apologies to him for an issue he was genuinely to blame for...
Troi goes over the top in "Face of the Enemy" that's borderline cringe.
"The Enemy" somehow contrives to make only Worf a viable donor. When people griped about TOS's "The Way to Eden" being crap because it fudged Chekov's character, it's easy to explain that (the dude had character growth and maturity throughout season three) than when TNG contrived plotting and changed character motivations, which leads to:
"Ethics". Worf's subplot is good, even if the rest of the crew becomes their season one up-nosed haughty selves again. But plot and character contrivance to make the guest doctor eeeeeeeeeeeeeeeevil for plotting sake became more and more obvious. Especially as, with the plot spiked, Crusher gets to spike with the uber-haughty "real research takes time". Yeah, that's true, but that's one piece of the puzzle - never mind Worf's unique set of circimstances. Worse, never mind the cheap plot development of "multiple backup organs", which is asinine in its excesses. "The Way to Eden" is a bona fide classic next to this over-contrived garbage. "Ethics" is largely cringe worthy of flushing for her subplot alone. Not that I'm opinionated or anything,
whine whine whine whine whine.
85% of the incidental music from seasons 5-7 has proved that milk ages far better. Ratings may have been better in 1991, but that was probably due to seasons 2-4 (esp 3 and 4) being repeated the most often at the time, as TBOBW cemented TNG in the zeitgeist and reruns truly got the ball rolling. No worries, halfway into season 5 the ratings became to go back down, but was still impressively popular...