Love 'The Lark Ascending'. My dad was a huge fan of British 'impressionism' and that was one of the ones I heard a lot throughout my life.
On the whole, I have to say that Delius' 'Song of the High Hills' transports me into another world. All my life I would wake up on a Sunday morning to hear that wonderful music. We played it at Dad's funeral - and I want it at mine.
Delius has been much underrated for past 50 years. Anyone who doesn't know - give him a try (my Dad actually saw him play!). Sea Drift - if you have the words - is heartbreaking.