Collies and Shelties are wonderful breeds.
We had collies when I was a child, and they would actually "herd" us off the road and back into our yard.
Both breeds are very smart and protective, and extremely gentle.
We too had a collie growing up, sweetest thing ever. Border Collie/Collie mis is great too, gives you the brains with the sweet disposition.
I am dog sitting my dad's golden retriever, he's a very well behaved mellow dog, great around the grandkids as well.