Summarize this article in one sentence.
The wild Himalayan blackberry is a tenacious invasive species in some parts of the western United States, but cultivated varieties tend to be juicer, larger, and more firm than wild berries. If you're going to plant some, it makes sense to pick one of these varieties, wherever you live, based on the structure of the cane, its growth pattern, and whether or not the variety has thorns. There are hundreds of strains and varieties to choose from, but knowing the basic categories will help you to make an informed decision.   If you live in a region with very cold winters, it's best to select an erect variety with thorns. These stand up to the elements the best and will provide the most solid-possible base for your climate.  If you live in a region with very dry windy summers, it's best to plant trailing varieties, which will stand up to the elements in especially harsh high-desert climates. Most varieties are able to grow in regions with at least 200-300 hours per season under 45 °F (7 °C), including USDA climate zones 7, 8, and 9 in the United States. Traditional training varieties grow much like the wild blackberry, shooting out suckers and sprawling all over the place, which means they'll need to be trellised with wires and trained along them to control the growth. Old fruiting canes will need to be removed, but new primocanes (new growth) will not need to be pruned. Trailing varieties often struggle in regions with especially cold winters, and won't fruit until their second year of growth. Evergreen, Marion, Obsidian, Chester, Hull, and Black Diamond are all popular varieties of trailing blackberry. These varieties of blackberry grow more like hedges, and will need to be supported with a T-trellis or a post of some sort. These varieties are easier to control and contain, but require vigorous pruning, shooting stiff new cane straight from the crown of the plant, rather than trailing along the ground. Many of these varieties will produce fruit in the first year of planting. Thorny erect varieties are the hardiest in cold climates. Illini, Kiowa, Shawnee, Apache, Triple Crown, and Natchez are all popular varieties of erect and semi-erect blackberry. Trailing, upright, and hybrid varieties are all now available in thorny and thornless strains, meaning that you can make your harvest a whole lot easier on your fingers. Thornless varieties do tend to be somewhat more sensitive to colder weather, making the thorny varieties a much hardier choice for most climates. Note that thornless varieties are more vulnerable to birds and other pests.

Summary:
Select a variety appropriate to the climate. Consider the hardiness of trailing or training varieties. Consider the easy planting of upright, erect, or semi-erect varieties. Weigh the benefits of thornless berries.