If you're doing Studies of Religion 2 Unit, then Living Religion or Oxford Studies of Religion. Excel Studies of Religion is a very good supplement book if you have extra money.
Business Studies - Heinemann or Leading Edge
Biology - Heinemann
Adv. Maths - Fitz, Cambridge, that woman (I forgot her name atm)
Adv. English - Depends on what texts? There are a few good ones...
It's epic. It help me make up for the fact that I did no work for PE all year. I did no summaries, and still got 91. It's basically the syllabus summarised.
Edit: also for maths Jones and Couchmans books are very good too.