For chem, don't get exambusters. Exambusters is a total waste of money (it cost quite a bit for what you get). It's just a collection of exam questions with the assesment reports stuck on the side, which you'll no doubt end up doing anyway. But it depends, if you're not going to end up doing practice exams then get it.
Lisachem is okay I suppose, it's kind of a brief run- down of the course, and as they say, the superfluous stuff has been cut out. I'm thinking of selling mine because I kind of regret buying it haha. Tell me if you're interested haha.
I also think that the jacaranda study card things are a waste of money, unless you use cards to revise.
I think A+ notes are worth getting though

I heard that leading edge is crap, but I've never actually looked at one.
Anyway, I hope this helps. In general, the ones worth getting are NEAP, Insight and A+. They are pretty awesome companies
