I throw pretty much whatever I have into my juicing, but I always have a lot of good foods anyway because I have also noticed that by changing my diet almost completely has made a huge difference. I usually do kale, spinach, chard (a spring mix),cucumbers, red apple (green is to sour, unless you like that), goji berries, flax seed, chai seed.
The Vitamix is a very good one too, but pricey. The Nutri Bullet does the same thing, you have to get everything from what you are juicing for it to make a difference. I hope this helps, it has been a lifesaver for me. God Bless.