I prefer Silver by far. He has a quiet yet sharp personality, that I found I loved to watch grow and develop, over the course of the story. Not only was his Pokemon team strong, but his will to win. His design was also quite dark and mysterious too, which matches his personality traits quite perfectly. An excellent rival. My favourite out of all generations.
On the flip-side, I really dislike Barry. He is just too fickle and rushed and his energetic personality isn't my cup of tea. His design is quite sophisticated, but his personality is what lacks with him, I feel.