I usually buy organic Balsamic vinegar. I forget the brand. But I don't like how diluted it is. It seems more diluted than the non-organic counterpart, which is also pretty thin.
Last christmas we got a bottle of pretty thick balsamic vinegar from a friend, and it was really good!
But dang, the aged ones are thicker but much more expensive. So it hit me......just reduce the one you have.
And it was really good. So...if you want a thicker balsamic vinegar, just boil it down for awhile.