I actually have a decent idea on how this could be run more effectively. It would be more of a Hall of Fame than an actual 'stockpile,' but it would be much neater than everyone posting everything.
1) There would be a thread manager who mantains the thread.
2) Two other people form a kind of commitee with said thread manager.
3) After the end of a battle, people may PM the thread manager nominating the arena used.
4) If five people nominate the arena, the group of three would vote and if two agree to put it in the Hall of Fame, it enters.
5) Also, if one of the three nominates an arena, and the other two agree, the nominations stage can be disregarded, and the arena would enter.
Any feedback? I wouldn't implement the idea as is at the moment, or any idea, as we don't really know what an epic match or a great arena actually are yet. Also, we really have better things to do.