Check out this declension table of "him" , tego does not appear anywhere! Why is that? https://en.wiktionary.org/wiki/Appendix:Polish_pronouns#Third-person_pronouns
We are told that do not use the pronoun at tye end of a phrase unless impossible.
1) Never put it at beggining (tego nie lubie)
2) not at the end unless its only two words and therefore to (lubie to)
3) luckily here we have 3rd option (nie tego lubie)
But theyve still stuck tego on the end :(
4) (Is it maybe cos nie and lubie are considered as inseperable? Is it cos it is more important to be clear what we're negating than actually being afraid of using pronoun at the end?)
5) So technically....
Tego nie lubie (wrong) Nie tego lubie (wrong) Nie lubie tego (good) Ja tego nie lubie (good)
Tego nie lubię - Correct, but 'tego' is heavily emphasised, which is too rare to be accepted here.
Nie tego lubię - Incorrect, because since the verb is not negated, the pronoun must remain in the accusative case 'to'. The translation for "Nie to lubię" would be: "It's not this what I like". Also too uncommon to be accepted here.
Ja nie lubię tego - Grammatically ok, and frankly we could even consider adding it. It's just a matter of how strict we want to be. This could work well when we have a contrast: Ja nie lubię tego, a ty nie lubisz tamtego. But then 'tego' would mean 'this one/person'.
Nie lubię tego - Without doubt the most neutral, common and natural version.