I think in the end (pun intended) True Detective S1 was quite shallow, whereas Dublin Murders goes pretty deep into the human mind. There are a few issues (only 2 or 3) that I did not like in Dublin Murders, so no 5 stars from me, only 4 and a half.
Rotten Tomatoes rating by "all critics is 89% vs 79% in favor of True Detective S1, but rating by "top critics" is 81% vs 83% in favor of Dublin Murders. This suggests that Dublin Murders is appreciated by more mature audience, whereas True Detective S1 is valued higher as "casual" (mainstream) entertainment.
Of course it makes no point to argue which is better, I just wanted to mention Dublin Murders because I liked it so much, and it had not been mentioned yet.