Okay here’s the rundown people.
Neither is better than the other, overall. Justice League had better plots they had two or three episodes to tell a story. And Justice League Unlimited wasn’t quite as mature as Justice League it just was more Kiddush, I don’t know how to explain it it just was. But Justice League Unlimited had episodes that focused on characters such as Booster Gold, they had the romance between Huntress and the Question, along with the weird romance between Batman and Wonder Woman (and I say weird because it just suddenly disappeared). Justice League focused more on the original characters than Justice League Unlimited did. In Justice League Unlimited you have the romance with Huntress and the Question, the Cadmus story arc, some focus on the fallout of Hawkgirl’s actions in the finale of Justice League, those are, the overall arcs of Justice League Unlimited. But Justice League did have the romance between Hawkgirl and Jon Stewart / Green Lantern, you see the creation of Metamorpho, Vandal Savage attempt to recreate history, a unique take on Wonder Woman’s Origins in the pilot episodes, Superman getting sent to a far-flung futureware where Vandal Savage destroyed the world, Hawkgirl’s betrayal of the JL and Earth.
Justice League is my personal favorite, but Justice League Unlimited is it equal, it just depends on your personal taste which one you will prefer.
But overall (note that I say overall), in some ways Justice League is better than Justice League Unlimited the reverse is also true, the two are truly equals.
A true and devoted fan of the DCAU,
CatAndHorseCrazy.2002
P.S. Check out my topic on the DCAU