I dont buy reference book for language subjects like BM and Eng except for the sastera/literature part. I used East view for the sastera/literature.

For math/add math, i dont buy reference book too, i bought workbooks only. sasbadi/oxford fajar/east view/pelangi also good

For science subjects, i used SUCCESS oxford fajar series. pretty good.
EST workbooks i used oxford fajar and other publishers as well.

Other subjects.. I don't know...