This was my first Flash issue during the Geoff Johns era. It became an instant classic. It was the first time I got to see what insight Johns gave to The Flash's enemies, who were always one of the more underrated Rogues galleries for a long time.
This issue explores one of The Flash's biggest foes, Captain Cold, and shows he's not just chosen for the legion of doom just so there will be a Flash foe in the group, but why he's respected by the rest of the supervillain community. It really boosted him in supervillain status in my book. It was here I think he became the badass Rogue leader figure he's been ever since.