Jennifer Lopez - can't sing
Jess Glynne - I remember a former work colleague telling me she had been to a Jess Glynne concert, and without thinking I said "oh does she sound less goat-y in real life?" and she looked at me all confused...
Little Mix - meh songs and they all seem miserable, especially Jade and Leigh Anne
The Beach Boys - I dunno why but I find their songs a bit pretentious
The Beatles - I only like a couple of their songs but wouldn't go out my way to listen to them
The Rolling Stones - not a fan of any songs
Dua Lipa - she's just average. I also think she looks sweaty and smelly all the time
Adele - I don't like her voice or songs, she has an annoying personality
Any singer who over-affects their voice to sound the same as other singers... I can't think of any proper examples now, but currently the singer in the advert for the George Michael documentary on Channel 4. He seems to be copying others.