The one that is part of the woman you care for. That's a start.

I'll venture a comment on chemistry here. Some people just do not smell very good to one another. Whether due to diet or health or natural makeup, there are people whose crotches you will never enjoy putting your face against. I used to be married to an alcoholic who drank 15 or 20 beers a day. Personally I do not like the smell or taste of rancid cereal malt residue and stale yeast.
Just my opinion.