Update 27th February 2016: New poll added
Given all of the new info and developments that we've had since the premiere, we thought that it was time to get a new poll going to see what the consensus on this was now. The previous poll is now closed, but still appears at the bottom of the post.
Updates from the original poll are:
-Felicity has been removed based on the final flashforward from the midseason premiere
-William and Samantha have both been named
-Curtis Holt has been added to the list
Remember to comment below with your latest theories!
The fourth season premiere ended with a flashforward to six months in the future, with Oliver standing at a grave.
Who do you think is buried there? Vote in our poll and then comment below with your theories!