If I was Green Lantern, I think I'd be a little upset that I, founding member of the Justice League and solo title star for almost two decades, got lumped in as just a "friend" of the Flash and not the subject of my own digest collection. I'm not trying to start something between Hal and Barry, mind you; I'm just saying.
Anyway, The Flash was of course a perfect character to headline his own digest; he was one of the most enduringly-popular members of the DCU, having ushered in the Silver Age of Comics.
"Doomward Flight of the Flashes" by John Broome, Carmine Infantino (a name we'll be seeing a lot of, I bet), and Sid Greene
"Space-Boomerang Trap" by Broome, Infantino, and Joe Giella
"Robberies by Magic" by Gardner Fox, Infantino, and Murphy Anderson
"Kid Flash Meets the Elongated Man" by Broome, Infantino, and Giella
"The One-Man Justice League" by Fox, Infantino, and Giella
"Captives of the Cosmic Ray" by Broome, Infantino, and Giella
...and of course there's a Flash text piece by E.Nelson Bridwell, who could probably knock off these character histories in his sleep.
Topped off with a nice set of covers by Ross Andru and Dick Giordano (those white backgrounds really work, too bad you don't see them much on comics anymore), and this is a solid collection of stories featuring the Scarlet Speedster!