Castor: I use the Jamaican Black Castor oil on my scalp to thicken my new growth and I also use the cold pressed plain Home Health brand (available at Wholefoods or online). I recently bought the Rosemary infused Castor oil for that essential oil touch. I hate the smell of anything strong that is not food-smelling but its a great scalp oil that I use every 2 days and add to my moisturising deep conditioner conconction.
Coconut: I love the smell of coconut. This is definitely my favorite. I use for weekly hot oil treatments (Friday night), wrap my hair with cling film/ saran wrap and wash out with shampoo (Saturday morning). I use the Nutiva or Nature's Way brands but just got gifted Dabur Vatika (Indian mix of coconut oil, lemon and herbs) which I will be using for the rest of the year.
Grapeseed: Ceramide-rich oil. I use this lightweight oil to seal my hair after moisturising. Its a heat protectant so good for summer weather. I am running out and will replace with hempseed or jojoba oil however or just use coconut.
Shea: I use shea from Nigeria. It is thick and heavy but makes hair super soft. I use this in the winter and over my braids. I also heat it up and use as a moisturiser when my hair is super dry.
In the fall of 2012, I will add Jojoba and argan to replace grapeseed. Updates will come then.