Here are some mistranslations from fan translated Japanese anime and TV shows that I collected some years ago. Since I watch subtitled videos very rarely nowadays, I don't really come across new ones.
Anime
Elfen Lied
この国で未成年を撃ち殺すなんて指令が出るとはなあ
I think that there are too few chicks around here.
おい、いい世の中になったなあ
Hey, you have a good woman don't you?
口を慎め!貴様、任務を何だと・・・
Shut up, don't even mention her!
俺たちは毎日、何の訓練をしてるんだ? 人殺し・・・だろう?
We never know where we'll end up tomorrow, don't you think?
In the above discussion the translator hasn't even done a "guesslation", but has just made stuff up. What is that called, "imagilation"?
これから摘出手術が行いますので
From time to time, you'll be taking these.
(This was said by a doctor after he had given the other character tranquilizers.)
やっぱり50口径の反動には耐えられなかったか
Guess I really do need tranquilizers from time to time.
拭えぬ血と涙によって少女は獣に変貌する
To question life's infinite struggle.
銀牙伝説ウィード (Ginga Densetsu WEED)
捕れるの?
When are you gonna show us?!
ここにはかつて、人食い熊の一団が人間を一切寄せ付けぬ王国を築いた時代があった
Here long ago, a huge battle was fought against a huge demon bear.
アジトは「牙城」と呼ばれた
He'd created a stronghold called Gajou.
牙城 translates to stronghold. There really isn't a reason to call it "Gajou" also.
だが、アカカブトに果敢に立ち向かう者達がいた
Akakabuto was going to fight to death.
一人のまたぎと…
One dog let the attack.
このことを旅先の総大将に知らせてください
It's an order from the leader.
母さんに持って帰るんだ
M..Mother.. I don't think I can get back..!
何だ、楽勝じゃねーか
It won't be easy then.
サスケ、考えがある
Sasuke, let's think it through.
馬鹿野郎!相手は土佐犬だぞ!俺がかなう相手じゃねー!
You fool! He's not a friend, he's just a Dog! I'm not his friend!
知るか!止めたのに聞かねーから
You should just stop it..
なんて情けねえんだ…
What sympathy he has..
そんなに変わりたきゃ、仏さんに変えてやるぜ!
You can't change yourself just from talking big.
桜、聞いてくれ!
Sakura, please don't!
さっきから総大将とか銀とか言ってるけど、ひょっとして、あの伝説の奥羽の総大将、銀さんの事か?
The story of Gin, the Boss Dog of Ohu... It isn't just a legend!? He's real?
この時、ヴィード、生後6ヶ月であった。
This time, it's Weed's story.
大将の器 (Episode title)
The tool of the leader
俺は高所恐怖症なんだ!
I shout at them but it does nothing..
TV Shows
Music Fighter
わたしは、いきたくありません ケーキがきらいだからです
I didn't want to live, since I don't like cake.
The translator has mixed up the words "to live" and "to go".
Utaban
この笑顔は…
This laughter...
Although 笑う can mean either "to laugh" or "to smile". 笑顔 simply means "a smile".
来ましたね…奴が
They've arrived... this pair
ちょっと軽く傷付きました
You noticed it pretty easily.
The translator has misheard the word 傷付く (kizu-tsuku) as 気付く (kidzuku).
This is from my own translation. :)
バク天!(Bakuten!)
This was a TV show where Razor Ramon HG (a "hard gay" character of a comedian) appeared.
来る者拒まぬこの体
They can't say no to my body
The translator was probably unfamiliar with the expression "来る者は拒まず".
マジ超ウケる
I'll totally take that!
The translator wasn't familiar with slang. It means "That's super funny!" (or what would be the current English slang equivalent of that :-)
HEY! HEY! HEY!
それこそ早う脱いだらええやん
That's exactly what they shouldn't do.
I can't remember what the context was for this one.
ド下ネタやないか
Is this some kind of dirty joke?
The translation is rather weak. "That's the dirtiest joke I've heard in a while" might be closer to the original.
めちゃイケ (Mecha Ike)
あったやろ?筆箱の中に《物差しが》
It is right though...
さのさん、かまないように
Sano-san, please don't bite...
The English word
bite doesn't have the meaning "to fumble or falter with one's words" that the Japanese word has.
カミ確率78%
Probability 78%
Here the translator has ignored the word altogether.
今に見とけよ、お前たち!
What are you looking at?
受験発表並みなんだけど・・・
These are "exam result" tears...
The translator has misheard the word "nami" as "namida".
ハロー!モーニング (Hello! Morning)
すずめの国から 巣立ち
From the land of sparrows, building a nest
笑っていいとも! (Waratte Iitomo!)
お腹かなり出ちゃってんのよ
If you don't hold your breasts, they will come out!
続くでしょ。20何人いるのか、今?
So how many of you are now in Tsunku Family?
Quiz Hexagon II
大どんでん返し!
Dai Don Den Gai!
Probably some sort of inside joke by the translator. :)
ぼちぼち辞め時ちゃうか!
Will you get your act together!?
やだ!ここが引退?やだ!
No! I'm just gonna retire here!
The meaning of the lines is reversed.
Uchikuru
僕らが天然素材で勢いある時に、歌を、CDを出そうと。
Since we look like airheads, we thought we'll be able to sell.
The translator probably did not know the group Yoshimotojirushi Tennensozai.
カバーしたの。
However...
僕らが歌ったのをまた自分でカバーした。
I found we sounded like frogs after hearing ourselves sing.
本当はこういう風に歌うんだよっていうこと?
You guys really sang that way you know?
FUJIWARA的には凡人!?
Fujiwara = Typical average joe!?
まあまあスベるし。
He's able to do whatever he likes.
セクシー!
Well, it's not really...
フルテンションでやったけど・・・
Mine is already not in use.
Gaki no tsukai
都内某グランド
Glove, bat, and ground.