Like so many here, I'm not so pronounced in my dislikes, nowadays. Earlier in life, I found the vibrato that classically trained singers affect to be very irritating, and the more vibrato, the more irritating. All classically trained singers do it.
Another irritation was with singers who didn't hit the note, but groped or slid up or down until they reached it. Like Doris Day among others.

Nowadays, Sarah Brightman and Doris Day are among my favourite recording artists.

Maybe it is because Her Indoors likes Country, Showbands, and Opera, and I like Jazz, Blues, and Folk. Exposure to, you see.