There are a few different blenders that professional chefs use, but the two most popular brands are Vitamix and Blendtec. Both of these brands offer high-powered machines that can handle just about any blending task you throw at them.
If you're looking for a top-of-the-line blender that will be sure to impress your guests, go with a Vitamix. These bad boys start at around $500, but they're worth every penny. With a Vitamix, you'll be able to make silky smooth soups, sauces, and even ice cream. Plus, they come with a ton of handy accessories like extra containers and tamper tools.
If you're on a budget but still want a powerful machine, go with a Blendtec. These blenders start at around $200 and can do just about everything that a Vitamix can do (minus making ice cream). So if you don't need all the bells and whistles, go with a Blendtec and save yourself some cash.