Actually, the worst romances I can think of involve specific episodes. The worst one in my opinion involves McCoy and Natira (he marries her because he thinks he's dying and takes off as soon as he has the cure).
And yet she was a young caring first class babe. His decision, from a male human point of view is completely incomprehensible.
Nerys and Miles just was a weird, uncomfortable, forced, eww kind of relationship. Deanna and Worf worked as there was some chemistry there, but I still wonder how well Deanna would have handled Worf's particular sexual needs. Seven and Chakotay was stupid, and seriously forced. It felt like a big F.U. to all the Janeway/Chakotay shippers. Trip and T'Pol's relationship worked for me, primarily thanks to the strength of Conner Trineer's acting ability.
It is weird that even after Janeway stated that she only wanted them to be friends, he still follows her around like a lost puppy with big pleading eyes. Buddy, move on! Just not with Seven... Oh wait, never mind.
Chakotay/Seven. Came out of nowhere, did nothing, and there was no chemistry between them. Worf/Troi had a tenderness that I liked, especially seeing a softer side to Worf. Kira/O'Brien wasn't so much a romance, more just a sense of intimacy between them due to the circumstances, Keiko obviously wasn't worried. Trip/T'Pol worked because of the chemistry between the two, shame then never gave it any proper closure.
My problem with Jadzia/Worf isn't with there being a gay Klingon, at all, but people are who they are, and that particular Klingon has been shown in multiple instances where his sexual preference was displayed, and ALL of them showed him as interested in women. Perhaps the most telling of those, in my opinion, would be from "Deja Q": if ANYONE aside from Worf would have been in a position to know Worf's deepest sexual desires, it would have been Q - and he gave Worf a pretty woman on each arm.
Chakotay and Seven was genuinely the worst. Both actors seemed incredibly unconvinced of their roles, but by that point Beltran had checked out and I don't think Ryan gave a shit. It was an afterthought tossed in the last season because what the hell! A stupid idea all around.
I don't really get the point here. Worf is straight. No one is denying that. Jadzia is a woman. That she has a symbiont that gives her access to the memories of other people, including men, doesn't make her any less of a woman. If anything, those memories probably made her a better lover, since she knew what it was like to be a man. Jadzia having memories that belonged to men might bother someone, but that's a different issue. Worf was intimidated by her experience, yes, but the story wasn't about transphobia.
I wonder if Troi would have been too fragile for Worf (in the normal timeline). The far future Riker being bitter at Worf over Troi....could it have been a death due to excessive Klingon sex? Sex that Jadzia was more than prepared for. Bruises, broken ribs, and all.