I'm not quite so keen on peaks and walks as they're a bit more like hard work and you don't tend to get little tea shops and pubs along the way :o(
But! You do get a sense of achievement and, as with the trails, they take you to some special parts of the world and the UK you might not otherwise see.
UK - outside of Scotland I'm not sure how many peaks we have in Britain - but I've managed to bag the 3 highest mainland peaks: Ben Nevis, Snowdon and Scafell Pike. Munros - plenty of these and I've got a looooong way to go on this list Around The World - money and time restricts me a bit here - I would like to have a crack at some of the main peaks around the world. I hope to try something like Mont Blanc first and see how I get on.