I love fresh juices and we have them all the time at our place. Here is a couple that I've made this week but the other girls are right so long as you drink them as they are freshly made any combination tastes great!

beetroot, carrot & orange
watermelon & mint
apple, celery & cucumber

It's always good to clean your juice machine as soon as you make the juice because if you leave it too long the pulp sticks to the machine and its just more of a pain to clean. If you use beetroot definately clean it straight away as it can stain.

Have fun.