Jay: Flash #134 (I think) by Mark Millar. Waid did good stuff with him too during The Flash, ditto Johns with the JSA.
Barry: JLA: Year One and the Brave and the Bold mini that spun out of it
Wally: Mark Waid's take. Nothing else comes close.
Bart: Only as Impulse. All else ain't Bart Allen. So yeah, Waid and Peter David, especially.