Fantastic responses, thank you all!
Costa Rica sounds really exciting, have a great time Chips ! We did California last Easter and it was fab! I would definitely recommend it for teen holiday! We still have some of the US to do, although we have done a fair bit already.
The safari in South Africa sounds amazing ajandjjmum ! This is definitely on my list possibly for next year. What company did you book with or did you package it yourselves?
chicken - I know we are lucky for her to still want to come with us, which she still does with pleasure and I cherish every minute as I know it will not last much longer. She prefers our family holidays to school trips anytime. We try and do our holidays on a high end budget, which she would not get travelling with school or friends 
Australia also sounds good but I think you need a longer holiday to really experience this country and the only really long one we get is the summer one, which is not suitable for Australia I think.
We ski every year and always go to different places in Europe. Never skied in the US. Where would you recommend there?
This flotilla holiday around Greece is really intriguing, Leeds2 who do you book this through?
Many thanks all, great suggestions!
I hope all of you have something exciting planned for Christmas too! We are off skiing, can't wait!