Your house is on fire but you're able to run in and save one thing. All people and pets are safe. What do you grab?
Mine is a crayon drawing my grandpa drew back in the late 30s/early 40s that my aunt gave me as a graduation gift. I had it professionally framed and matted a few years later, but before that I had it replicated in tattoo form. It is easily the most important item I own, though it's worth nothing to anyone outside of my family.