Pigaloos.
If you want your new guinea pig to bond with you and your family, do not put a pigaloo in the cage. Or, at least, take it out of the cage during the day or when you are home. If the pig has a place to hide, he or she will always retreat to the safety of their hiding place rather than learning that you and your family are big, harmless food delivery systems. The more you handle your new pig, the more quickly he or she will bond.
I do use a variety of shelters in my cages, especially when introducing a new pig to the caviary to minimize the stress of the move. But I don't recommend them for most folks.
If you have a pig question, please let me know in the comments or drop me an email and I'll try to post an answer if I know the answer.