PvE, definitely. I far and above prefer PvE in any MMO. But PvP has its place as well. I dislike the concept of player-killing, being able to come up and kill any player you like without consequence. Black Desert made a decent start on how to handle that, but I don't think it was enough. Things like tournaments, guild wars, dueling and the like, on the other hand, are harmless fun. Totally voluntary PvP is always the way to go.