You know, the thing about green smoothies that bugs me is that they're tacked on greens meant to hide under tons of sugary fruit. I LIKE greens. I have no interest in putting them in something that hides them so that "you can't even taste them". This applies to all food, really. I just find that kind of cheap and gimmicky. I like things to have a purpose in a dish beyond just added nutrition. Like, butternut purée in mac and cheese tastes awesome. It's not about trying to sneak in vegetables.
Which is why this is how I like my green smoothies:

Two bunches of spicy, peppery arugula, zingy lemon and ginger, and sweet, but also tart, fragrant mango. Barely sweet (I probably couldn't sell this one to people who love their strawberry banana smoothies) and the arugula IS the flavor, boosted by the other ingredients.