I love the king’s pawn opening, king’s knight variation for its simplicity. However everybody has their own favorite, so I recommend taking the time to read up on popular openings and try them out to decide your favorite.
As white I like to play the Queens Gambit, because it often leads to more positional games, and it allows for c4, d4 and e4, where as kings pawn usually amounts to just e4 and sometimes d4. As for black I like the Caro Kann/Slav Defence, because it’s a good response to both e4 and d4, and it also leads to much more positional games. My favourite would be the Advance Variation of the Caro.