I agree about the greens - I bought the juicer primarily for vegetables, since I think that's where the real value of juicing is at.
I made another new combination last weekend: carrots, cucumber, celery, kale, and spinach. Nice and green, and the cucumber toned down the flavor from the dark greens. I didn't use quite as much carrots this time, so the blend was more balanced. Very tasty! I might go a bit heavier on the dark greens in the future. I understand that some people find them a bit too bitter, but I don't mind.
I also plan to try some additional flavoring ingredients, like parsley and cilantro, in the near future.