"I do not like it."
Translation:Nie lubię tego.
Similarly to your other question, 'lubić' takes accusative, 'nie lubić' takes genitive'.
Also I wonder (I have no way of checking) if "Nie podoba mi się to" is accepted as a translation, it seems so much better to me because it can actually be about some unspecified "it".
"Nie lubię tego" sounds either like a beginning of a sentence, lacking some masculine or neuter noun at the end, or like people fighting for a "Dislike" button on Facebook - seriously, google "nie lubię tego" as an exact phrase, most results will be about Facebook :D
I just checked "To mi się nie podoba" which was not accepted as correct answer but it has the exact meaning. If you hear the sentence "I don't like it" in a movie in most cases it will be translated as "Nie podoba mi się to" or "To mi się nie podoba" depending if the emphasis is on the feeling or the subject. "Nie lubię tego" would be used mainly if it is about a taste in wide meaning e.g. food, music, art, etc.
Because those two are very different grammatically.
In a sentence with "lubię", "to" is the direct object. That's why it's "Lubię to" and (negated Accusative -> Genitive) "Nie lubię tego".
In a "(nie) podoba mi się" construction, the thing that you like or dislike is the actual subject of the sentence, so it has to be the basic, Nominative form: "to".
Different forms of "to" are needed dependend on the gender of what it describes (here it doesn't describe anything, it's a dummy pronoun - that's why [this/that/it] all work) and the function it serves in the sentence. Here, the positive sentence (I like it) took Accusative, so when the sentence got negated, it took Genitive instead. The Genitive form of "to" is "tego".
Technically, 'jego' is one of the Genitive options for "ono" = "it" (they depend on how the sentence is constructed), but I struggle to find a context when the exact sentence "Ja jego nie lubię" would sound natural. Some neuter noun that is 'not liked' would need to be mentioned before.
It's as if you tried writing "It is not [this/that/it] that I like" (so you negate 'it' and not 'liking it').
However, even if you really wanted to say that, that's still wrong. If you negate 'it' instead of 'liking', then the object of liking is in Accusative. After all "lubić" takes Accusative, it just changed to Genitive because of negation. So that would be "Nie to lubię".
Yes, we should avoid that if there's another possibility, however in such a short sentence there isn't really one. Your word order negates "go" instead of "lubię", so your sentence looks as if it was supposed to mean "It is not him who I like (I like someone else)". But to be correct even in this meaning, you'd need the emphasized form of "go", i.e. "jego". "Nie jego lubię". This is a strange sentence but technically correct.