I loved Lassie as well. My favorite show in the series was when Lassie, accidently got lost far from home after going into a big delievery truck. Timmy was so sad, until the day Lassie came bounding over the hill and was home again. I think I cried over that show it was so moving. Wish I could have a copy of it I would love to watch it again.
If i had to answer in the way of books it would be "White Fang," or "Call of the Wild," or "Lassie.'
Another book I really love is "Winderdance" by Gary Paulsen. It is a true story. If you like humor this book will have you laughing so hard you will be in tears. He was training sled dogs to run the Iditarod, and never before owned a sled dog and the methods he uses will amaze you. His wife never knew if he would get home alive or in one piece, for often they ran hundreds of miles before turning back to go home. But he did get them trained and ran that race many times until his health problems caused him to quit racing.