Of course, it depends on a lot of things, mainly how tired you think you'll be and how much you'll value your rest. If you hop on the Narita Express, you'll catch the 15:43 if you're very lucky or else the 16:13, and get into Tokyo Station (say) at 16:45 or 17:18. (If you want to go to Shinjuku, that's roughly another half-hour.) You'll want to arrive back at NRT on the 8:28 arrival, so you'll leave Tokyo Station at 7:30 or Shinjuku Station at 7:07.

I love Tokyo's nightlife, so for me it would be a no-brainer. If I were arriving in C/J or F, I'd definitely go into Tokyo. If I were arriving in Y, I'd probably want to rest instead.