Now? I have two distinct collections of spices. The more commonly used spices are found over the stove, and the rest are in the cupboard. Over the stove, I have cayenne, oregano, thyme powder, bay leaves, parsley, basil, garlic powder, and salt & pepper. The majority of my recipes will use at least one of these spices, and they are in Ikea-brand bottles with a pour spout on one side and a shaker on the other.
As for the spices in the cupboard? I have cumin (powder and seeds), rosemary, thyme leaves, paprika, garam masala, sage, chili powder, curry powder, chili flakes, marjoram, poppy seeds, peppercorns, nutmeg, cinnamon (ground and sticks), cloves, ground ginger, ground allspice, cardamom (ground and seeds), ground tumeric, coriander (ground and seeds), mustard (powder and seeds), sesame seeds, saffron and dill. Phew! Definitely better than my first collection.
A few of these spices are used for curry dishes (cumin seeds, garam masala, curry powder, cinnamon, cloves, cardamom, tumeric, coriander, saffron), some are for specific dishes (sesame seeds, dill, ground ginger), some are for roasts (rosemary, thyme leaves, paprika, mustard powder), others are used alot, just not as much as the ones on the stove (paprika, cumin powder, chili powder).
It's difficult to say which spices one should always have, because it ultimately depends on what kind of cooking you do and how often you do it. My collection grew mostly because of the different recipes that I started to make. Many of the curry dish spices were only acquired a couple years ago because that's when I started warming up to Indian food (and now a food I used to avoid has become a food that I adore). So, explore the different spices out there and happy cooking!