Ok so I have flip-flopped on this topic for a while and my FINAL guess is Future Barry Allen Is Savitar.
We know all of the clues to Savitar's identity but there is one point I feel most people missed. Savitar told Barry that they will meet very soon and it occured to me that Barry is going to meet his future self in the next episode. Also if you think about it I could totally see emo Barry in that Savitar suit.
Let me know what you all think below, don't get mad if you don't agree remember we all bullied the people who correctly guessed Prometheus's Identity.