Acai berrie powder or Goji berries would be great to add to these kind of smoothies. Very high antioxidant content of both as well as many many health benefits.

Personally i like using a lot of green vegetables such as kale and spinach. The green vegetables particularly green leafy ones are the most nutritious to consume. You should use a lot more vegetables then fruits. Don't get me wrong fruits are good just using too much gives you a lot of unnecessary fructose. And your liver can only hold about 50-100g or so.