So I went into my rewatch of The Sopranos and The Wire with the notion that The Wire was the greatest TV drama of all time, just a hair ahead of The Sopranos - and I come out of it feeling the same way.
I don't know; maybe if I had watched them in the other order and The Sopranos experience was the freshest thing in my mind, then I would reverse the order - but I don't think so. While they are both triumphs of character and plot development, I think The Wire wins out because of relevance. It is such an intelligent look at so much real world stuff. The Sopranos is an amazing voyeur experience into an unfamiliar world but The Wire is everything.
They are both amazing achievements though, which I consider among the top artistic things I have witnessed in my lifetime. I look forward to rewatching them every 6-8 years for the rest of my life, and for it to be a real treat every time.