LSE and Kings College London are two of the best unis for business. UCL is good too (in London) but only does Information Management for Business (which I'm currently doing) - it's basically half computing and half management.
Royal Holloway is near London and also is good for business/management.
Sorry to say but Herts uni is NOT GOOD. Aston is good but there are MANY MORE better universities that do business. Here is the following list of universities and courses (the names of the courses might not be exactly correct as I am doing this from memory) that I would advise you to consider:
Oxford - Economics and Management
Warwick - Management, International Business
LSE - Management
Kings - Business Management
Bath - Business Management
Nottingham - Management
Edinburgh - Business Studies
Loughborough - Business Studies
Royal Holloway - Business Management
UCL - Information Management for Business
City - Management
Don't put a lot of faith in university rankings, especially not the subject rankings. A lot of people will say "oh well university x has a good business department" when in fact the university AS A WHOLE is inferior. Employers don't care what the department is like when it's a degree like business/management, they care about you and what university you went to. For instance a lot of people rate City's management degree because of Cass Business School, but City itself is actually quite bad and their management degree is not affiliated to Cass because Cass is only concerned with postgraduate. Similarly Durham's business degree is NOT ACTUALLY AT DURHAM, it's in their crappy Stockton campus.
Most importantly do research yourself. A lot.