'best' = vita mix or blendtec - it will obliterate everything so you get max nutiritional value, you can even make soup from scratch and ice cream too. awesome machine but = £399!!!!!!!!!!

mine was a gift :) do a youtube search of blendtec and broom or ipad - yep someone actually turned an ipad to dust in it - idiot.
but a juicer is different this will juice (extract the solid and give you just juice) of say fruits like apples, oranges, pears - hard fruits. melon, mango etc is not going to work, carrots are good for it and celery, so you'll get like tropicana smooth, or apple juice. these you can pick up for £15-30 in argos. dont bother with the expensive ones.
tbh of the typical range of blenders all have the same power motors = same results just marketed up with different designs etc etc so go for something cheap and see how you get on.
it sounds like you want a blender is more versatile but if you dont like the smoothies, pulp and bits in your juices and thats all you want it for go for a juicer ...