I've been low-key impressed by Expressive Firedancer.
I don't find myself in the aggro spells deck very often, but when I do [[Expressive Firedancer]] is the two-drop I want. It frequently attacks for 3+ as early as turn three; the threat of activation triggering discourages the sort of even trades an opponent would otherwise want to make against aggro; and once you hit five mana it becomes a must-answer threat. [[Tome Blast]] and [[Burst Lightning]] are particularly nice pairings, as ways to get magnum opus without inflating your curve.