For myself, it depends on the use.
In the winter I often get itchy feet and itchy scalp so I use peppermint and tea tree oil. It works great. It’s also great for clearing sinus problems used with a steamer. It’s got anti fungal and anti bacterial properties.
Lavender is a nice relaxing oil which brings about a sense of peace and tranquility.
It’s also good as an insecticide and helps repel mosquitoes.
There’s citrus scents like orange, grapefruit , lemon or lime. Lemon grass is also used as a repellent but is very refreshing.
Then there are woodsy scents like cedar wood, pinewood, fir, frankincense
Of course there’s rose scents, apple, vanilla, thyme, rosemary .....
You can get almost anything from nature in an oil form, some being essential oils. Personally I like most of them.