Various books I've used over the years, with reviews.
Warning: I'm not a native, so what I like and think is a good cookery book will be different from what you would be served in India/Pakistan/Bangladesh. These books will be much closer to what you would be served in a good Indian restaurant in Britain.
The Curry Secret by Kris Dhillon
The New Curry Secret by Kris Dhillon
Indian Cookery by Madhur Jaffrey
Classic Italian Cooking by Valentina Harris
By which I mean cookery that our grandparents would recognise as British; clearly we have benefitted from many cultures bringing their own cuisines to our shores and a Chikken Tikka Masala is just as much a part of the local cuisine as a roast dinner (some even claim that it originated in Glasgow). British cookery is a corpus of many different dishes and contrary to popular belief contains some gems. Obviously, it focusses on stodgy and filling sustenance to get you through the winter. Similar to some germanic cuisine, but with our own island twists.