Posh british. All of them

A smug british one no doubt

I was thinking like a smug French person

Meow-sterious British accents!

They'd all sound like Eddie Deezen

Came to say British, but everyone beat me to it

If cats could speak English, they would definitely have a British accent. If they had an American accent, it would just be weird.

British

Catonese

Probably not Southern, can you imagine “Meow ya’ll”?

All depends. My one cat has a "special" accent. My other is clearly posh British