Morrison's run is largely considered the definitive JLA run. Because feats, and heroing, and Morrison is god.
Much as I love Morrison and everything he does, I consider that a "meh" run.. I get his intention, getting back to basics in a quasi-pre crisis lineup. But it felt like he was playing catch-up on the "epic" Marvel storylines they've been doing for the past decade.
For me, this will always be THE gold standard JLA:
Keith Giffen is an underappreciated genius, and one of my favorite writers ever. He actually turned DIONE into someone I can enjoy reading, lightening him up from Starlin's "takes himself too seriously" rendition, while still keeping him a bad-ass genius.
This JLA series was FANTASTIC. Maxwell Lord and Martian Manhunter, Guy Gardner and Martian Manhunter, Lobo, Guy Gardner and General Glory (LOL!), Kilowog, and G'nort, Lobo, Blue and Gold, Fire and Ice. And Lobo.
Literally had me in tears, sometimes. It was the anti-1990's.
People hated on it precisely because it was more humor oriented, and somewhat a parody of super hero comics. But to see Batman playing straightman to their antics alone is worth the price of admission.. Telling Carter Hall this:
With Dark Knight Returns still relatively fresh in mind?
But it wasn't all fun and games.. There was a lot of genuinely good character development in there. Maxwell Lord in particular had a character arc that started with him being a corporate swindler, to a pretty likable character who tried to do the right thing, but was insecure about how to do it, and became one of J'on's closest friends. (Infinite Crisis, of course, ruined all of that.)
I could go on, but I think I've made my point. Awesome run, awesome series, hilarious, introduced many key characters still in use today, and done by one of the best writers on the planet (Just look at Giffen's resume. Five Years Later is one of the top Legion of Super-Heroes runs, for example.)