In an episode of Batman Beyond, an older Superman was recruiting Terry as a member of the Justice League. The episode was ok but nothing special, especially since there were so many legal problems that they had different voices for people and for instance couldn't even use Wonder Woman, and had to replace her with BARDA for god's sake.
The Justice League Unlimited episode that Batman Beyond is a part of is "Epilogue", which is one of the finest JLU episodes out there in my opinion. Without spoiling anything, I can just say that it definitely wraps up a lot of things and in a very cool manner.