The best opening I believe is the one you're most familar with. If you know Center game like the back of your hand, it's better than playing the Sicilian for the first time.
I personally like the Ruy Lopez for white, and and the Nimzo Indian against 1. d4 as black and against 1. e4 as black, I just make the best responses, as it can go many different ways
e4 or d4