Last week's cover for the final Flash issue by Geoff Johns is something of an homage to George Perez's cover to Crisis on Infinite Earths #5:
I count 48 rogues in eight rows. Unfortunately, I can't say that I recognize them all. With a little help taken from the Geoff Johns board, here's the list I've assembled.
Row 1: Shade, Dr. Polaris, ?, Blaquesmith, The Thinker, Folded Man, Rival, Professor Zoom
Row 2: Mr. Frost, ?, ?, ?, Inertia, Rudolph West
Row 3: ?, ?, Replicant
Row 4: Peek-A-Boo, Brother Grimm, The Suit
Row 5: Abra Kadabra, , ?, Murmur, Zoom
Row 6: Weather Wizard, Double Down, Turtle, Grodd, ?, Mirror Master, Pied Piper, Trickster I
Row 7: Dr. Alchemy, Fallout, Captain Cold, Captain Boomerang II, Fiddler, Colonel Computron, Heat Wave, Clive Yorkin
Row 8: Plunder, Magenta, The Top, Girder, Tar Pit, Vandal Savage, Cicada
That still leaves nine unidentified rogues. Perhaps not surprisingly, most are partially obscured by the central logo. There are some guesses that I'm not confident enough to include yet. Such as Warden Wolfe on Row 1, President Thawne on Row 2, Trickster II and Mr. Element on Row 3, and Chillblaine on Row 5. Any suggestions or corrections?