Let's talk about Corrector Yui. Here's the MAL link.
Basically, the series was created in the 90's, but it takes place in 2020. In this world, computers have advanced so far that you can upload your actual consciousness onto the Internet (or as it's called in this world, ComNet) and enter a virtual reality. Our protagonist, Yui, however, is horrible with computers. So obviously, she's the one who has to go into the virtual world and collect the seven programs to stop the evil virus Grosser from taking over the ComNet.
The anime was licensed by Viz ages ago, and was dubbed/subbed for the first 18 episodes... And then dropped. No fansubbers have ever picked up the series, either. So it's impossible to watch the remainder of the series in English.
I'm really sad about that, because I want to see it.
The manga, however, is an interesting case, because there are actually two different versions of the manga. The first version, which is the original incarnation of the series, was made by Kia Asamiya, who, from what I gathered, normally did shounen series. This was his first attempt at shoujo. This series was only two volumes long, and I was able to read a scanlation online. It's alright, but incomplete.
The second version of the manga was made by Keiko Okamoto, and it is much more shoujo than the other one. From what I understand, it follows the anime more closely. It's five volumes long, and though I was unable to find scans of it online, Tokyopop had licensed the series years ago and published it, complete with flipped artwork! I had to buy copies of it to read it, hehe. There's also a sequel series for this version, Corrector Yui Ver. 2, but that was never translated at all. I'd love to buy the raws for it someday.
So, my thoughts on the series? It's really fun. The vision of the year 2020 from the 90's kind of reminds me of the 2015 scene in Back To The Future Part 2. It's just so cheesy and idealistic. I really enjoyed Yui as a protagonist. I can't put my finger on what it is, but there's just something about her that feels very...realistic as a 14-year-old girl. She was just believable, I guess, in personality. I also found it really amusing how, throughout the manga, you can clearly see problems with how computers have essentially taken over every part of life, but. It's never, ever portrayed as a bad thing. With some of the crap that goes on, you would expect someone to stop and say "Hey, maybe this isn't such a good idea" but no one ever does, and I find it funny. Oh, and I also really loved War Wolf's design. He's very cool looking.
Again, I just wish the anime was available in English past episode 18. I watched the first episode (the dub was probably one of the worst I've ever seen), but I really don't want to continue it if I know I won't be able to understand what happens next.
Maybe someday a fansubber will pick it up. I can only hope.