If the question is 'if the railway had no subsidy and was driven entirely by the market, what services would run?
Then the answer is:
Most of the London commuter network - with higher peak fares than now (probably considerably more expensive).
Some intercity routes - London to Birmingham, Manchester, Leeds, Newcastle, Bristol, Cardiff, Norwich + Eurostar.
Maybe some commuter services in Birmingham, Scotland, Leeds, Manchester.
Err, that's it.
Also, being completely commercially driven, salaries for those working for the operator would be somewhat lower.