Brilliant black. I saw it after getting my blackberry blue and wished I'd gone with the brilliant black. It's a little more involved keeping it clean though.
If I had to choose a dark color (black, dk. charcoal or blackberry), I would go Brilliant Black.
That said, color choice is so personal that asking never solves the problem or you won't like what you hear. If you truly like both black and charcoal equally, then take a Poll to get an answer.
Every car I've ever owned was black, including my 98 ZJ. For sure black is hard to keep looking clean. I went with the dark charcoal pearl this time and I am so happy that I did. It even looks great in the sun and doesn't look nearly as dirty as black. I think you'll be happy with the dark charcoal.