Herb plants that have a strong smell?

I m planting herbs below every window of my house and would like a plant that has an especially strong scent to plant below my fathers window. He is elderly and quite sickly, and he complaints that his room smells like "old person". He uses many lotions and compresses for his achy joints and the odour of these creams tend to linger. Obviously I d want something that smells pleasant and preferrably an edible plant. Any suggestions?