Black swans are extremely rare, I thought. I don't have a preference but on the one occasion I saw a black swan I was very excited as it was a once-in-a-lifetime moment!
White swans are everywhere, I like them but don't get excited about them.
I think they're all beautiful! Black swans are native to Western Australia, so we get a lot of them here, but I also recently saw some in NSW, which gave me a big surprise as I didn't know they were found elsewhere. White swans are also lovely, though.
I love black swans & they are actually the bird symbol of Western Australia however I cannot say that black swans are my favourite as there is just something about white swans that make me feel like I'm in a fairy tale.