Dale Peters recommends Qube in London http://www.qubeglobal.com/careers-vacancies/ who are currently advertising for a Graduate Developer (C# and databases). He says:

“I had an interview with them just after my first year (almost three years ago) in the hope of securing a Summer placement but they were looking for someone that could work for them on a permanent basis. They seemed like a good company to work for from what I saw at the interview and seemed to have a good training scheme in place.”