World's Finest

 It was pretty inevitable.  Once WB started the excellent Superman cartoon, having him meet Batman was just going to happen.  So they had a three part episode/movie.  The commentary doesn't remember quite if it was released in prime time as a movie, but it was released on DVD as one.  By the way, as always, the commentary on this episode is really fun.  I wish they could have done more commentaries, which is something I rarely say.  I usually want  a doc about the movie.  End digression.  Naturally Bruce Timm took the name of the three parter from the long running comic book (back when Clark and Bruce were best friends) and it does fit the scope of the movie.  It's odd, they act like they are the only heroes on the Earth, though by now we know there are plenty more.

So the Joker has 20 pounds of green Kryptonite and wants Luthor to buy it from him  for one billion dollars- after he kills Superman.  Batman takes a trip to Metropolis and the fun begins.

Not only do our heroes not see eye-to-eye, our villains don't exactly get along either.  One of the best parts is Luthor and the Joker having a meeting while Harley and Mercy fight back and forth across the screen in the best tradition of old Merry Melodies and Loony Toons.  You never even see them fighting, you hear it, and then there's the aftermath when Lex leaves.

All in all it's a great story, with the possible exception of Bruce romancing Lois and how quickly it happens.  Add into that her discovering Bruce is Batman... how many people know his "secret" ID now?  I can think of at least seven, and eight if you believe (like I do) that Gordon has it sussed as well.