Now, dhampyresa asked for current fandom, which means I have fewer decisions to make. I always want people to be into Utena, or Gokusen, or Ranma 1/2, but those are constants. By 'into', here, I'm going to assume 'producing fannish things' rather than just 'liking'.
Taking all this into account, it's actually a really easy choice.
Reasons you, YOU, should love Batman Beyond and write fic and make art and meta and stuff:
Terry Mcginnis, an angry, violent young man who is also a total sweetheart. I like him too much to be able to describe him easily; his introduction is running off a Joker-wannabe who's bothering a woman on the subway, and next we see him kicked out of the school boxing club for a fight he didn't start. He'll fight entire gangs just to keep them from going after anyone else. A genuinely nice dude who eliminates a lot of my problems with Batman simply by being an entirely different character.
Excellent ladies! And lots of them. A surprising and gratifying amount.
All of the main character's important relationships save one are with female characters. You know the usual format of these kinds of shows: a boy and his manly mentors and his dude friends ... and then maybe his mom and girlfriend over to the side. But Batman Beyond reminds me a lot of Fullmetal Alchemist in the way it makes female characters central in the ensemble cast even with a male hero: you have Terry and Bruce, sure, but you also have Terry and Barbara, Terry and Max, Terry and his mother, Terry and Dana, Terry and tons of secondary and tertiary female characters. Does he have guy friends? Who cares?
Gotham City, as seen here, is so heavily Asianized you could easily put it as an expat-heavy ward of Tokyo. 1) lots of Asian or potentially-Asian characters, 2) worldbuilding fun (if it's in Jersey, why are 90% of the building signs written in hanzi/kanji and hangul?), 3) crossover potential galore!
Parts of this show are really cool and intense, and other parts of it are the Batman sitcom you always wanted.
Cyberpunk! Not that I'm 100% certain how to define cyberpunk, as a thing, but this is definitely it. Terry fights crime wearing a robot Batman suit, and you could spend thousands of words arguing about how much of Batman is a sleep-deprived teenager vs. how much of Batman is a robot suit vs. how much of Batman is the legend of Gotham City vs. how much Terry is any or all of these things -- and I would have already if the show hadn't practically done it for me.
Long story short: this is Batman for people who hate Batman. If you like Batman, you might like it! If you usually hate Batman, but enjoy ... anything ... this may be the show for you!
Also, there is literally an episode titled 'Terry's Friend Dates A Robot'.
December meme over here, still mostly empty, give me more stuff to talk about please.