How about Los Infernos.
It's like Los angeles, accept, ---- well less angelic.
A different approach might however to give it a name that indicates it's actually supposed! to be a really friendly and awesome place, and just isn't, ---- after all cities like new York started sounding quite nice.
On this basis, and going with the new York theme why not call it New Rome or New Paris.
A final thought might go with the commics approach to city names, ie, pick something that sounds! like a city but isn't such as Gotham or Metropolis (which has to be the most boring city name ever).
On this basis I'd suggest Mortham.
Lots of cities in English speaking countries end with "ham", an old Anglo saxon word for town, eg, Nottingham, Bermingham or Grantham.
In the same way Dc came up with Gotham by putting together goth, ---- ie gothic, violent and nasty with ham for town, how about Mortham from the word mort, meaning the latin for death.
I think that's imho the best idea with these, after all you don't want to follow gta too exactly.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)