I covered the first (and still best) story here, but haven't read the two middle ones (Supes and Spidey vs Dr. Doom and the Parasite, Batman and the Hulk vs the Joker and the Shaper of Worlds) in ages. the final one, Teen Titans and the X-Men sure makes me miss those teams. even if Wolverine was turning into Batman by then. his brown and tan costume is much better than the blue and yellow one. these days I don't even know who is on what team. and that's just sad.
marketing was the reason for both Wonder Woman and the Hulk in being in the second story, and it feels shoe horned. better to have ditched that part of the story and had more fun with the secondary cast- Peter in Metropolis, asking Lana Lang out (always did have good taste) and Clark in NYC working for the Bugle.
the Batman/Hulk is... a good looking story, but just problematic. the characters are so disparate it's hard to team them up. they did a good job, but really, Cap or Daredevil would have been so much more fun. the dumb Hulk is my least favorite version, and they actually gave him more brains than normal. I've never heard of the Shaper before or since. more fun is to be had in the introductions to each story.
and then we have the X-men/Teen Titans. this is a good story, but the weird continuity that these stories set up (I never cared what world/earth/universe they happened in) becomes problematic, since both the JLA and Avengers are referenced in this one. but it's a fine piece of work, good writing and lovely artwork, even if it tries to be more important than it is. and Darkseid dies... again. I didn't care for this story at first, since it "replaced" the original JLA/Avengers, but I've come around.
especially since I finally got my JLA/Avengers.