The gold standard will always be Game of Thrones. I still believe that would be a far better show if they just looped the opening credits for 50 minutes every week. And to your point, that's probably the only opening that has had any sort of cultural relevance outside of TV since....Friends?(I'm not counting the Law and Order noise) Odds are you'll hear the band play the GoT theme at the next college hockey game you go to. All the other HBO prestige dramas(Deadwood, Wire, Sopranos, Boardwalk) have competent, acceptable opening sequences, but your band isn't playing Tom Waits.
Some of the Netflix openings are great. The opening sequence for
Bojack Horseman is incredible.
Glow has a cool opening too, though obviously not original music.