Two brands come to mind - Imagine's "Organic Creamy Butternut Squash Soup" which contains everything organic, and has somewhat of a sweet taste perhaps from the rice syrup, and ... Campbell's Select Gold Label Golden Butternut Squash soup.
The Select version is, to my taste, the best of the bunch. The soup is so thick in the aseptic box that it requires you to scoop it out - it's like a thick puree rather than a thinner liquid which is what most soups (including Imagine's version) are.
I add fresh vegetables, such as mushrooms and chopped up squash, to the Select soup. While it does not contain the same degree of healthy ingredients as the Imagine version, their soup tastes like a gourmet version you would have had a better restaurant. While most companies try to jazz up their cans of soup with pasta or various combinations of vegetables, the Campbell's Select line is, in fact, a premium line, and tastes much richer than almost all the other soups. With the butternut squash soup, you can be creative and add a large combination and variety of vegetables to jazz up the soup, such as diced carrots, a leaf or two of spinach - my favorite two additions include yellow squash and sliced mushrooms.