Historical version 7 of Anglia Railways (view current version)
Run out of Liverpool St into East Anglia.
Used to run a very useful 'Crosslink' service up from Basingtoke, through Feltham & Brentford and then heading around part of the North London Line before heading eastwards. Discontinued September 2002 due to 'lack of use', they tell me - although they confessed the service was serverely limited by the post-Hatfield crash restrictions and never really recovered from that.
Now we just have to wait for Crossrail...
Their express trains to deepest, darkest East Anglia are very nice; far superior to the [Great Eastern Railways]? trains, being both faster, newer and cleaner. Catch them if you can!