i cant choose three. most frequently i cook with cumin, coriander, smoked paprika and cinnamon for spices. i use a lot of spice blends from north africa and the middle east like harissa, garam masala and baharat. grains of paradise are used a lot around here, and tellicherry pepper.
in the non-spice world i use a lot of garlic, various salts, preserved lemon peel, dill, thyme, rosemary, basil... my favorite flavor is from chile peppers though. i ALWAYS have (get this) aleppo pepper, urfa biber, chipotle mecco, de arbol, cascabel, ancho, chimayo, gujillo and new mexico green chiles. its a sickness i have. this is why i couldnt stop laughing when someone suggested i give up nightshades and capsicum for my MS- NOT. GONNA. HAPPEN.