Robert Downey Jr.
I became insanely obsessed in 2010. I got a screenprinted body pillow with various pictures of his face as a gift my sophomore year in college. I slept with it every night for 2 years. I cried real, salty tears when I had to throw it away because it wouldn't fit in my car for my cross-county drive.
I bought and watched ALL of his movies within a month. He had an amazing supernatural/fate romance phase in the 90's that I am STILL all about.
And his Christmas song got me in the spirit for sure.