Whole spices usually hold their character longer, while ground spices offer convenience and speed.
If you cook often and do not mind a grinder or mortar, whole spices like cumin seed, black pepper, coriander seed, cloves, cinnamon, and cardamom are a strong starting point. They store well and give you more control.
Ground spices are still worth keeping on hand. Paprika, turmeric, ginger, chili powder, and curry blends can be practical staples when time matters.
A balanced pantry often mixes both. Use whole spices where texture and freshness matter most, and keep dependable ground staples for fast weekday cooking.
When in doubt, buy based on frequency. Start with the spices you actually reach for each week, not the ones that only sound impressive.