The Batman Superman Movie: World's Finest (1997) on Netflix

Strapped for cash, the Joker offers his services to multi-billionaire Lex Luthor by saying he can kill Superman with his new Kryptonite statue. Trouble is, not only is the Joker an untrustworthy criminal lunatic, but he can never get too far away from Batman. And so Bruce Wayne and Clark Kent meet, in and out of costume, each one wary of the other but no where nearly as explosive as when Luthor and the clown get on each other's nerves. To say nothing of henchwomen in hand-to-hand combat and a battle royale with killer robots. Oh, and Bruce dates some reporter named Lois...