Matthew 26:7-16, Mark 14:3-11, John 12:1-8, and Luke7:36-50.
In these descriptions of four very similar events, we see that John emphasizes the fact that Mary was at the feet of Jesus. On the other hand, Matthew and Mark emphasize the anointing of Jesus' head as with the anointing of a king. Most scholars agree that Luke describes a different event with a different woman. I can imagine a conversation between Matthew, Mark, Luke, and John in heaven.
Matthew says to John, "Hey I really like what you did with your account of Mary anointing Jesus."
"Oh yeah, thanks, you know how it is, inspiration of the Holy Spirit."
Mark chimes in with, "Yeah, John, but you really emphasized the bit about Mary always being at the feet of Jesus. I wish I had thought of that. We all saw her anoint his head but you also brought out her humility in stooping down, anointing his feet, and wiping them with her hair."
John replies, "Yeah, I guess that is how I always saw her. She was at Jesus' feet when he was teaching. She fell at his feet when he came to raise Lazarus. And then she poured perfume on his feet and made quite a spectacle of herself with her long hair."
At which point, Luke breaks into the conversation and says, "Yeah, she looked a lot like that other woman who wiped Jesus' feet with her tears. I mentioned her in my gospel record, you know."
Matthew, Mark, and John chuckle at the doctor and Mark says, "Yeah, good connection Luke."
John adds, "All those feelings of unworthiness and sorrow wrapped up in both of those events."
Matthew looks over at the Holy Spirit and says, "Wow, talk about divine inspiration!"