I highly recommend Royal Purple synthetic, I have always been a mobil 1 user.
The taping noise is well known for NSX, it is normal, by switching to Royal Purple, it will quiet it down a bit.
Heard many good things about Royal Purple, so I decided to test it out in my Supra first, did not want to take chances with NSX, I was a bit shocked by the results, my T61 single turbo is spooling noticeably quicker than before. EGT reading is also slightly lower than usual.
After good results in the Supra, I also changed the oil in my NSX with Royal Purple. Engine is definitely a bit quieter at idle even with the hood open.
Best thing is that they are not too expensive, $36 for 6qts.