I dono about the hardness and softness.. But my favorite brand of pencils, the only ones I'll use, is Faber Castel. I find the others I try don't seem to come onto the paper as vibrant. And you can blend them together by drawing on each other. Though, I might just be smitten with them, so I don't like any others. XD
But it's cheaper to buy them in a pack at shops like Big W, and that. Buying them one by one is about $1 per pencil.