Click to see Spoiler:I’m finding it really difficult to believe that Harry's a horcrux. Dumbledore has said more than once that the reason Voldemort couldn’t possess Harry is because of Harry’s ability to love. If the part of Voldemort’s soul that inhabits his body couldn’t reside inside Harry, then surely a measly little rouge part of his soul wouldn’t be able to accomplish it either.
My Horcrux List (I'm inclined to believe Dumbledore)
2.Slytherin's (Marvolo's) Ring
3.Slytherin's (Merope's) Locket
5.Ravenclaw item/Gryffindor item
7.The part residing in Voldemort
Dumbledore also said that the sword was the only remaining relic of Gryffindor's. But in another of the earlier books (forgive me I forget which one) the sorting hat says that it once belonged to him (Gryffindor). While I don't believe that either of these items are a horcrux, it would be incredible poignant if the sorting hat was a horcrux, being as it's the tool to divide the school and destroying it would ultimately bring them together.
I do think that the 5th horcrux is probably something of Ravenclaw's. I've been trying to think what it could possibly be though.
eta:Click to see Spoiler:Oh, and I think Snape is good - not evil.