I find that I always miss the scenery of my youth the most. I adore mountains covered in big, tall trees, a la the place i lived when i was 1 - 5. It makes me feel the most 'at home' of any place. I do like others, but if i had to choose a favourite place, i'd say mountainous forest.
Do the places you love/yearn for most tie in with what you were surrounded with when young?