In relation to MG's post, the thing that makes walking special for me is that I get to hit the hills with my dad most of the time. I'm glad we both have something we enjoy doing together and it makes us work together with navigation and decision making.
Other than that, the sheer elation of seeing cairns and trig points is my favourite part just now !
I can remember climbing Culter Fell when I was 15 and it was snowing and sleeting and the cloud was down, I only had trainers and my £20 waterproofs on, my dad was behind me and I bascially ran to the top of the hill and bust my lungs with happiness, I think the other guys who were there got a bit of a fright. I vowed never to look at another hill after that soggy, horrid, wet, slushy day. But the hills got the better of me and now I'm in it full time