If you're talking about doing your own juicing and not buying caned juice then you want to buy a Masticating Juicer.
Juice covers a lot -- virtually anything can be juiced if you're doing this yourself. Fruit juices contain a lot of sugar, but can also be powerful antioxidants, but vegetable juices can be very valuable. Wheatgrass juice is great. So this depends on what you mean by nutritional juices. Most important, avoid anything that's not organic. When you juice anything, you use a lot of it, and that enhances the amount of harmful chemicals that exist on whatever you're juicing. But if you're talking about vegetable juices, since all vegetables have value, you increase that value by juicing since you use more of it and don't destroy the enzymes unless your juicer produces a lot of heat.
don't spend your $$$$ on sugar!! check the nutritional label