I think all Nokia phones are beautiful, they haven't released a Windows Phone that hasn't appealed to me yet. I currently have the 925 and it's awesome.
BUT, I've always loved the blue HTC 8x. Absolutely sexy.
I have an 8X and think it's quite sexy as it is BUT that 8S design is easily the sexiest to me in any color (however blue always did catch my eyes a bit more )