New Map Suggestion
Preamble: I think the reason other maps don't often work out (read: get popular) is because they deviate from the general concept of the MOBA. And why ARAM works is because it doesn't change the core concept. Use your champ to kill people and take buildings.
Having said that, I'd love to see a map that operates like ARAM but only in one direction. For example, red team is on offense, and blue team plays defense. The game would alternate "phases" based on either a 10 minute timer expiring, or upon destruction of the nexus. All players begin the game at level 18.
Example:
Red team needs to destroy blue teams nexus before the 10 min mark. If they do, they're given a point. If they don't, blue team receives a point. Once that phase ends, the roles are reversed and the game begins again. First team to 5 points wins.