My vote for fastest aggro deck in the format is Red-Green Aggro Energy. Many of the creatures in the red-green archetype start off small, but once they start attacking they outgrow everything. The key to this deck is using your energy properly. There will certainly be games where you won't know what to do because you have so much energy, but it's in the games where you must decide to allocate your shortage of energy that will matter. Because most of your important creatures use energy in some fashion, it's that much more important to decide how to use it when you do. It's an awesome archetype to try out in any case.