Aidan is fairly popular over here - I know three. Aaron has become extremely popular recently (last ten years or so)
In my life, I have only met two other males with the same forename (Hilary) as me - one was in the same class at school.

I named my daughter "Rebecca" some thirty-plus years ago, thinking it was unusual - she was one of three in her school year and we have since met hundreds. However, my son was named Samuel, and this is still pretty unusual.

AS with everything else, these things go in fahionable cycles.