I splurged a few years ago and bought a refurbished vitamix - it is WONDERFUL for smoothies and you get all the fiber too!
My latest addiction are kale smoothies!! I start with handfuls of kale and add a couple of organic apples, a banana, carrots, pineapple, and whey powder for protein, sometimes a handful of almonds too. I've even added some pumpkin. It's DELICIOUS! My 6 yo even loves them. He says they look like a pond, but they taste great. ;)