I mainly dislike names because people I know/have known with those names have been horrible etc. Others I just find "meh".
Emma, Sophie, Fiona, Caroline, Charlene, Vicky/Vicki/Vicci, Denise, Yvonne, Marlene, Chloe, Gemma/Jemma, Claire
Ian/Iain, Darren, Darrel/Darryl, Tyrone, Kevin, Keith, Gavin, Peter (esp. when shortened to "Pete"), Gary, Gareth, Wayne, Phillip, Maurice, Dennis
Plus most of the names that are trendy or popular at any given time.
And made-up names.
And any of the names associated with the Inghams (and most other YT/influencers tbh).
Oh and Colin! I was going to be called Colin if I'd been a boy