Don't worry too much about which opening is best, just find a system you like and track your own results. Don't play anything unsound because when you get to higher levels all your experience on it is wasted since people will play properly against it.
d4 is probably easier to learn a system for than e4 as white. But if you like e4 than playing it is perfectly fine, in fact if you exclude sicilians e4 does better than d4 as an opening for white.
The sicilian scores well for black, and is diverse enough that almost everyone can find a system in it they like.
In case you haven't figured it out yet, asking "Which is the best chess opening" in a chess forum is like walking into a comic book convention and asking which superhero would win in a fight.
Basically, you start a geek fight.