What the hell did Samantha ever see in Durwood? Either one of them.
It helps than Nathan Fillion would have chemistry with an inanimate carbon rod.
Really? Because I didn’t really buy Mal/Inara. YMMV.
You beat me to it. She would have been better off turning him into a dildo than just leaving him as an asshole.
I never got the relationship between Jackie and Hyde on That 70’s Show. Friends with benefits, sure, but not an actual “relationship.”
Jess and Nick on New Girl. The show ran off the rails when they hooked up (partly because Jake Johnson is terrible), and has never come back.
I was going to point to two specific characters, but to save time, every single couple, potential couple, excouple and couple-to-be on Grey’s Anatomy.
The Chandler-Monica thing was supposed to be a one night stand only. However, then actors ended up showing a lot chemistry, so they went further with it. Which is surprising in a way, since in real life, Perry and Cox apparently did not get along.
Rachel and Joey were for the opposite reason, they went with it because Aniston and Le Blanc were good friends in real life, but they quickly discovered that they did not pair well together.
I diagree with those who say that Radnor had good chemistry with the Mother, most of their scenes together consisted of her talking and him quiet/reacting. The actresses quirkiness sold it, not any great chops by Radnor.
Exactly what I was going to post.
So I’ll offer my fallback entry: Lucy and Ricky. Their relationship was antagonistic at best, and Ricky was an oppressive, emotionally abusive husband.
What did Fred and Ethel Mertz ever have in common?
Vaudeville. 
They hated each other in real life. 
Either way, you know that never would have worked.
Heh. They seemed more like a real couple than most people on TV. They owned an apartment building, apparently had roots in entertainment, and they kept getting sucked into the wacky schemes of one of their tenants, and had developed the contempt of years of familiarity.
Frawley didn’t really hate her, he just didn’t know why Vivian Vance was always complaining about him. She wasn’t a happy person, forced to play second fiddle to Lucy, even made to stay overweight to keep Lucy looking younger and more attractive. Frawley was a happy guy though, Desi hired him even though he couldn’t find work because of his reputation as an alcoholic, he promised Desi he’d always show up on time and sober, and he never let him down.
The seemingly irresistible sex-goddess treatment that “True Blood” afforded Sookie was what finally made me give up on it about halfway through its run. Was there ever a hetero male character on the show (aside from her brother) that DIDN’T want to bone her??
I just didn’t see it. I had trouble with the initial pairing of Sookie and Bill, but went along with it hoping they might eventually work up some chemistry. Then Sam was in love with her. Then Eric wanted her. Then the Cajun serial killer from s1 (forget his name - Remy or something?) wanted her. Then Sookie and Alcide!
No, I couldn’t buy that this fairly plain, not-too-interesting, and often exceedingly shrill cretin could have every man South of the Mason-Dixon line panting for her. I suppose they could have explained it away as enchanted fairy blood or something after I stopped watching. But to me that was more unbelievable than the idea of vampires and werewolves.
They never, ever did, and as a matter of fact, it got much worse. At least, early on, he was supposed to be this charming, olde-South gentleman vamp in a town of inbred hillbillies. Then he turned out to be using her. Then he turned out to be using her at someone else’s command. Then it turns out he had been stalking her for a while. Then it turns out he set up the whole first meeting to give him an excuse to bite her. Then it turns out that he was using her to go against the person who commanded him to use her. And so on. And with each revelation, she broke up but eventually forgave him.
I don’t mind him being an utter creep, but I object to her being so pathetic that she keeps forgiving him.
I was always disappointed that Seinfeld only threw us a taste of the Elaine and Jerry trying “sex to save the friendship” story arc. (I never seem to see those in syndication either). There was a really good undercurrent between them.
I do agree it was probably better they stayed apart. No hugging no lessons.
Yeah, Ted and Robin didn’t work in How I Met Your Mother, and it was frustrating how the show kept pushing “Ted and Robin, no wait, Ted gets over Robin, no wait, Ted and Robin!” Especially how they drew out Season 9 so much to do a few more final “Ted Gets Over Robin” stories, only to undo it all in the finale. That was incredibly poorly handled.
But you know what was stupider? Ted and Zoey. Their whole relationship made little to no sense, most of the conflicts were predicated on a non-issue which Ted had already solved, and their relationship lasted way too long despite all that. Sure, Ted and Zoey wasn’t as blatant or interminable as Ted and Robin, but it was completely senseless and felt like it was only there to create drama and set up unrelated situations. Ted taking years to get over Robin is at least believable to a degree.
100% agreed on How I Met Your Mother. What the hell were they thinking?
I disagree with the OP on Veronica Mars, though. Sure, Logan was often an asshole, but he was an asshole with heart. I bought their relationship as that of two deeply wounded people who couldn’t get past their brokenness.
This.
Completely ruined the ending.