Use East Coast regularly from Huntingdon via Peterborough to York and back, cheap enough booked online in advance, yesterday cost £34.60
Reliable, fast, clean carriages including toilets and polite staff, so no complaints from me and now have a loyalty points scheme too
Quite often pay the 1st class supplement on the way back, well worth the six or seven quid extra for a nice afternoon tea and comfortable seat in the quiet carriage.