Dark leafy greens always go straight to my brain. I love kale juice mixed in with things like apple and lemon. You can also do a savory version with tomato and cucumber.

I love a grapefruit, handful of spinach, 3 tbsp of ground flaxseed, with water as needed. Also love watermelon, strawberries and ginger when in season. And there is nothing better than a young coconut opened and the coconut water and meat inside blended together. This is an amazing energy rush! I get the coconuts at our local food co-op for $2.49 each.

I love equal parts carrot, apple, and pear. Sometimes with a little knob of ginger.

Try this:
http://www.food52.com/recipes/4240_happy_healthy_long_life_juice

my go-to is equal parts of carrots, celery, spinach and parsley. It looks weird, but tastes good and really gives you a burst of energy.

Ginger and carrot!