I just watched "Dramatis Personae" and I can't stop hating on it. WEAK.
Oh come on, that episode is hilarious. That's one of the only season 1 episodes I can still watch and enjoy, if only because of how hilarious it is when Sisko yells that he'd sooner kill Kira than leave the station.
Characters performing CPR on an injured crewmate, shouting "Come on, breathe!" Such a cliché! I cannot look directly at the screen when this happens. I think every doctor character on Star Trek has done this, but especially bad: Robert "Wooden" Beltran in VGR's Coda.

Eddie Roth, you rule. Most laugh out loud hilarious post I've read in a long time! Most of my picks have already been mentioned. "Plato's Stepchildren" and "And the Children Shall Lead" make me embarassed to be a Star Trek fan and watching them made me so angry I wanted to throw my TV out the window. Some moments I hate that may not have been mentioned -
1) Close-up on Troi's foot massage and other pillow talk in "The Price": Gross, and the only episode of TNG season 3 I really hate.
2) McCoy and Kirk doing very forced-sounding baby talk in "Friday's Child" and Spock struggling to understand it (although I like the rest of the episode)
3) Sisko having to sing in the DS9 episode with the aliens (with stupid face tattoos...come on, couldn't they be a little more creative with alien make-up?) who like to play games
4) The alien woman on the surface who melodramatically whines to Picard about how they're all doomed if he doesn't save them in "Deja Q"...I wished Picard would say, "calm the hell down woman, I'm trying my best!"
5) Every bit of body language and dialogue by Corbin Bensen as Q2 in "Deja Q". Aside from him and the alien woman's hysteria, I thought the episode was perfect, so I was disappointed with how they dragged it down.