Sonia and Tina should not be together, as they have nothing in common

They were better as friends

Agreed. I would also say;
Chesney and sinead (cs) as no chemistry
Steve and Michelle (CS)
Fiz and Tyrone (cs)
Marlon and Carly (ED)
Lee and Whitney (EE) as no chemistry
Kim and Vincent (EE)

Sonia and Tina are the worst couple ever.

Fiz & Ty
Ches & Sinead

(Ironically, probably the two longest serving couples on the Street right now?)

Carly & Marlon
David & Tracy

I agree with every couple already mentioned. I'd also add Phil and Sharon. FGS, end this disaster of a relationship already and let Sharon regain some of her lost self respect.

Ste (Hollyoaks) and any bloke other than Brendan
Stendanforever

David and Tracey (Emmerdale) there's no way a fit bloke like him would look twice at a scank like her.

I only watch EE & CS but I find most of the couples ill-suited, probably easier to make a list of the ones that do work

Roy and Cathy from Corrie. I can't believe the writers have put lovely Roy with this messy fool. He deserves better

I can't believe I forgot Roy and Cathy as I can't stand their coupling. I probably forgot as I try to block them from my mind. I feel it was out of character having Roy move on so fast and Roy is lovely and Cathy is awful

It's going to get worse too.

Exhibit A

Exhibit B

Other Exhibit A

Other Exhibit B

Pretty much every couple on ED right now.

Zak and Joanie (uuuuurggggh)
Marlon and Carly (double uuuuurrrrrggggh)
David and Tracey (just why?)
Robert and the Miserable One (zzzzzzzzzzzz)

Worst couples

EastEnders

Sharon and Phil
Ian and Jane

Casualty

Connie and Jacob
Alicia and Ethan

The worst relationship on soap right now....Starry (Ste+Harry for non HO viewers). Awful. No chemistry and extremely unsuited. Only staying together to appease a small and I mean very small minority of the viewers. Everyone I seen can't stand them but HO are flogging a dead horse but they probably have been since the beginning of this unrealistic pairing.

I also don't believe in Lauren and Brad Neighbours or VJ and Billie H+A. Both unrealistic. Lauren and Brad are being described as long lost loves who have found each other but no they are atrocious together and Laurens behaviour upon the affair was awful. She moved on from Matt extremely quickly and told Amber that she loved Matt but not as much as Brad and Amber forgave that😨. Please tptb don't keep them together. As for Villie as they're being called in certain parts. What can I say? Well they are just wrong wrong wrong in all ways. Talk about ruining a good character in Billie putting her with VJ and my God has he destroyed her. Why tptb thought this would go down well ive no idea.

CS:-

Steve & Michelle - zero chemistry. They shouldn't interact in any way, shape or form.
Eileen & Phelan - although I can't wait for Eileen to discover he's only using her. Ha ha ha!

Zak and Joanie. Horrible. Ruined Zak completely.

Cain and Charity. They bring out the worst in each other.

This duo are who sprung to mind when I read the tread title. A terrible romantic pairing. I wish they had kept them as friends.

Roy was the type of character who would never enter into another romantic/sexual relationship after losing his first love. The production team chose to ignore that and have him move on from Hayley within a matter of months. Ken Barlow he is not.

Cathy showed some promise when she first arrived and Melanie Hill is a capable actress but they've gradually worn away the interesting elements of her character and turned her into yet another dumb and incompetent buffoon with a gob.

"Vendetta ... isn't that a posh ice cream?"

Lauren and Steven in EE. I just don't think they 'click' in any way.

She is very pretty, he isn't all that anyway.

Agreed Ells. 100%.

Disagree. They're brilliant together.

Zak and Joanie- Zak better go back to Lisa!
Marlon and Carly- make no sense.
David and Tracy- With David ask Tracy to marry him, I mean come on he can't force her.

Chesney and Sinead- no chemistry, CS better get their arse off the couch and split them up.
Maria and Luke- no chemistry again, usually dislike Maria for reason.

Sonia and Tina- At first I like them but I start to get bored of their relationship.
Steven and Lauren- I prefer Lauren with Peter, I dislike Steven already.