As white, I play 1. e4. Against 1... e5 I play Ruy Lopez. It gives white really nice play and many times puts black in a very difficult position. Against other defenses, black is generally the one who chooses what line is played.
As black: Against 1. e4 I play Scandinavian. It gives black a solid and relatively equal position. Also, most players aren't very prepared for Scandinavian (it's not a relatively unpopular opening), so they don't know how to deal with it properly and many times giving black a slight advantage. Against 1. d4 I usually play a King's Indian Defense and transpose to a Benoni. This leads to pretty sharp play giving both sides many chances.
What is the best opening move when you are playing as white? And What is the best opening move when you're playing as black? Give me some reasons why.