I don’t have much experience with crocheting yet but my absolute favorite yarn so far is Cotton from Svarta Fåret (Black Sheep). I only change the thickness of the yarn there when required.
You can buy the yarn directly from them or through various subcontractors (I use Adlibris)
I realize that I have started collecting some yarn and as they are so beautiful I have them out in the open and not in a box and I use various fruit bowls for my yarns.
MissFihn 