That is so funny, I just replied to your comment on the lettuce thread. Bananas are a great way to cover the leafy spinach taste, you only need half of one! You could also try half carrots and half spinach if you still taste the spinach and don't like it.
I use a small single serve Hamilton Beach and it blends up just fine as long there is enough liquid in it. This is what my smoothies look like
after blending it up. I tend to put frozen bananas, frozen strawberries, half spinach, half carrots, greek yogurt and enough water or half applesauce/water to be able to blend it up.