:( He had a hard life.

Harry's life may have been hard, but he had people who loved him and would give their lives for him. People he could easily lean on and hold his secrets. Who would never leave him. Snape didn't. He was alone and hated - for the most part - by everyone. (Besides Lily, but that didn't last very long. And she did ditch him, even though her reasons are fair, I don't think Ron, Hermione, or Sirius would act the same. They wouldn't have ever given up on him) At the end of the day, Harry did have a lot of sadness in his life, he also had much more light. And alternative. No competition, Snape.

Tom may have been in an orphanage but he was also good looking, powerful, and smart. He could have easily choose a happy and easy life. Snape has proved, no matter how much bad you have or have had, you can always choose the right way.

Snape's life was harder, but as to childhood, Harry's was worst.
Flowerma, I think you're extending "childhood" too much. In my opinion, when Harry turns 11 and Hagrid tells him he's a wizard, he's not a child anymore, he's a pre-teen.