I'm kind of surprised you don't care for Batman Beyond. Hell, in many respects it shared much more in common with Silver Age Batman stories (fantastical and "wierd" enemies, Batman running around carrying an Eggbaby

), but with the added bonus of down-to-earth, albeit teenage/high-school personal drama...
The high school stuff was what bored me the most. I think the first and third seasons are okay, and
Return of the Joker was excellent, but aside from the addition of Max, the second season does nothing for me. In the first season, the emphasis was more on organized crime and corporate corruption, but the second season dropped that in favor of a more "teenage" focus, and it got ridiculous how many students and teachers at Hamilton Hill High turned out to be involved in criminal enterprises or got transformed into super-powered lunatics or whatever.
It was also a fascinating character study on Terry, since it was the first time I had the opportunity to explore how/why a non-Wayne would take up the cape-and-cowl, which is essentially the entire point of Return of the Joker.
Which would've been more fascinating if Terry hadn't just been Peter Parker in a Batsuit. The whole series is basically "What if Spider-Man were Batman -- in the
future?!" Not that I actually realized the connection the first time I watched the series; I just didn't find Terry a particularly worthy successor to the cowl. He was just some punk kid who stumbled into it. I could never look at him and think "Batman."
And the new rogues' gallery never interested me. The villains in B:TAS actually had interesting personalities and motivations and hang-ups. The villains in BB were just powers and gimmicks, no personality, no reason for doing what they did. Like Shriek. Here's this sound engineer who invents a sonic weapon. Okay, fine. But when Powers tells him to put on a costume and personally assassinate Batman, he just goes ahead and does it.
Why? Why is this engineer hiring himself out as a killer? What drives him? The writers gave no thought to that. They literally just had their artists draw a bunch of character designs for villains and wrote stories about those drawings. The villains were as superficial as you could get.
The only times I really got into the show was when it revisited characters and threads from B:TAS. I was actually invested in those characters and ideas, and they interested me far more than the new stuff. (I did like Max a lot, though. Terry should really have dumped that bland Dana for the much more fascinating Max.)
Also, I couldn't stand that constant headbanging heavy metal music. A huge letdown after the gorgeous orchestral work of the previous DCAU shows. Music is an important part of what gets me emotionally invested in a show, and if the music is offputting to me, it keeps me from caring as much about what's happening onscreen.
Oh, and "Epilogue" never happened. I don't care that the conceit that the storyline was supposed to be the next DTV movie after ROTJ; it's stupid, world-shrinking, and destroys any and all dramatic and narrative weight to the entire series.
I couldn't disagree more. It actually made me feel for the first time that Terry deserved the mantle of Batman. (Although at the time, I hadn't yet seen RotJ, which might've made me better disposed toward him.)