I also liked "The Greatest Story" and it's a good choice to show how JLU gave third-tier characters treatment deserving of first-tier ones. It was written by Andrew Kreisberg, who also wrote "Legends," one of the few highlights of JL Season 01, and it's just as funny. I can't remember if I began reading Giffen and DeMatteis' Justice League International comics before or after seeing "Greatest Story" but I found that they dovetailed perfectly. And any episode that goes beyond the original seven--who still had too many episodes of their own in JLU--to be a relief.
"A carpet is large enough to accommodate two sufis, but the world is not large enough for two Kings." – Yavuz Sultan Selim