Pages #2, 6, 16, 20, and 22
Clipped from Comic Art Fan: Sean Murphy did a 2-part "Titans" story written by Mark Sable in what would have been the Titans' first encounter with the Flash's Rogues gallery. Unfortunately, those issues were not published because of a continuity error involving Bart Allen's death.
Dork Note: I would be pretty cool if DC or Marvel collected all their unused pages and covers that have existed over the decades and put them into a single volume. I would love to see the "what could have been".