I'm surprised to say that my Nutribullet is my favourite kitchen gadget. Surprised because I'd been aware of things like that for years and I never had any intention of buying one.
A good friend bought me one when he knew I was diabetic and going on a 'health kick'. I think the idea was to make smoothies, and so long as you're very careful not to get carried away with fruit (you don't need any at all) they do help you to cram a lot of raw vegetables into you - the volume and texture of e.g. lots of raw kale would be very unappealing unless blended.
I've hardly used it for making smoothies at all, however. It's great for other stuff:
The "Newcastle Diet": The small cup & lid are great for "shaking the shakes", and the big cup and the blender are great for making soups, i.e. after boiling the veg in stock, and letting it completely cool for safety reasons, blending for 30 seconds then re-heating in e.g. microwave makes a very palatable soup. If any kitchen appliance fits hand-in-glove with an "ND" it's this.
Also great for blending combinations of nuts / a few raisins / prunes etc to make balls of very tasty, fatty, and just-sweet-enough things for 'dessert'. This can be a bit addictive however, and the results are extremely high calorie, so needs doing with care. A great way to make 'nut bars' / 'nut balls' for when out hiking.