Naruto is the only series where I make a big deal on the romantic outcome. Other works of fiction it was either as I figured or the romantic subplot, if any, was so negligible to the plot that I just didn't care. If I may give my two cents to series with controversial romantic outcomes:
Ichigo 100%: I was pretty okay with it. High school and how it changes you can be unpredictable, and at least the author made sure the time spent between Junpei and Aya was NOT a waste of time. They still shared the same goal they did before, and their characters were treated with dignity.
Harry Potter: Meh. I'm mostly going by the movies, so if there's anything I missed in the books, let me know. From what I saw, Rowling did not SPECIFICALLY hint at Harry and Hermoine being a thing (ie have a previous generation of characters mirroring Harry and Hermoine, comparing Hermoine to Harry's mom, etc), and their characters remained consistent and admirable throughout most of it in my opinion. Ginny did come out of nowhere, but she had no impact on the main story. I dare say I even found it kind of cute, the way they were tip toeing around Ron. Ron and Hermoine...I'll be honest, didn't really like it. Though not on the same level of toxicity of SasuSaku, it irritated me how Ron was being a jerk to Hermoine (and in some parts Harry). I was just "Okay, either Ron has to give a major verbal apology, or Hermoine needs to move on. Pick one!" I more or less accepted it, but if it's true that Ron got drunk before they exchanged vows, well, that's a problem..
Thundercats 2011: A bit complicated for me. I think the writers did deserve criticism on how they handled it. They probably should have downplayed some of Cheetara's actions towards Lion-O (especially the kiss on the cheek), and the love triangle was rushed through way too quickly. That being said, once Tygra and Cheetara WERE together...I actually liked them as a pair. They had pretty good chemistry, in my opinion.
Interesting to note, Dan Norton recently talked about his plans for Season 2, and apparently Lion-O was eventually going to marry Wilykit (there would be massive timeskips for both characters to make this work).
The Avengers (Hulk and Black Widow): Didn't care for it. It was pretty forced, but so many other awesome things were going on I was able to ignore it. It wasn't going to work out anyway, so to me it was nothing worth getting upset over.
Bleach: Honestly didn't care. I read Bleach only to finish it, and most everything about it went downhill. But I will give Kubo kudos for giving his readers a heads up on what would be, instead of Kishimoto lying about the opposite.
Legend of Korra: I'm fine with it. Korra's romantic life was really the least interesting thing about her. You could probably cut out the last two scenes of the final episode and nothing would change. And for the most part, I actually DID like the development between Korra and Asami. Yes, they weren't being heavy-handed about their sexuality, but sexuality is complicated, and many people often don't realize they're into another gender until some point later in their life. If we had them spell it out that Korra was bi, in my opinion it would have been a distraction. It would be "In another episode of KORRA IS TOTALLY GAY! Part 2!" I think the way they handled it was perfect for a kid's show. It's like Ian Flynn (the writer of the Sonic Comics) said when asked about including gay characters: "I wouldn't mind including gay characters in a story if possible, but we're not going to put it in the reader's face, going 'LOOK HOW PROGRESSIVE WE ARE!'. The only difference between you and an LBGT person is that they like the same gender as themselves. That's it." In addition, if you're looking to make an endgame ship a surprise, this was how you did it. Korra and Asami had interaction, and I can go back and say "Oh, the signs were there!" (Asami by Korra's side when she was first in the wheel chair, Korra writing only to Asami, and their interactions afterwards).
If there's one criticism I would have, only ONE of the girls should have dated Mako.
Batman (Animated Series and Killing Joke): Not a fan. I'm okayish with it in the animated series since most of it was off screen, and Barbara was at least a consenting adult then. Still, they didn't need to make a comic where apparently Bruce knocked her up and then she miscarried. Killing Joke move...the less said, the better.