Okada and Omega are quite a bit better than current AJ and Rollins (Not their fault, Okada and Omega get to wrestle a more insane style). Absolutely start watching NJPW, wrestling has never been this good before with the level of characters they have and the roster they have.
Best thing is, Okada and Omega aren't even the best in the company IMO (that goes to Tetsuya Naito), but the rosters so stacked that its not even a controversial opinion. I'd say there's ten or so wrestlers that wrestle on or above the tier of Seth and AJ Currently. Here's some match recommendations:
Kazuchika Okada Vs Hiroshi Tanahashi, New Begging in 2012 (Not the best match, but a great starting point for Okada)
Kazuchika Okada Vs. Hiroshi Tanahashi, Dominion 6.16 (2012)
Kazuchika Okada Vs. Hiroshi Tanahashi,