There are 3 sources of information that will help you know what makes you happy.
Fantasy. Do you let your mind wander? If not, you should. As your mind meanders (also known as day dreaming), what do you day dream about? For me, I fantasize about sharing with my children new things, traveling to new locations to face the unknown, and watching my wife's eyes light up when she sees something new.
History. Sit down for a few hours and look back over your life. Start at your earliest memories ... walk year by year, season by season, scouring your historical landscape for those moments that brought you the most joy. Catalog them. For me, it involved going to new places, like the ghost town my mother tried to find on a trip and visiting china town in San Francisco and flying to Hawaii when I was 8 to live with my aunt and uncle for 3 months. The excitement of the newness and discovery excites me deep inside.
Experiments. Try new things ... new things that seem way out of character. The experience will highlight 1 of 2 things for you. Either you were right in avoiding them before, in which case you've validated your stance, or you find joy in them. People change over time, so don't be shy about trying something again that a few years ago seemed appauling, boring, or otherwise unpleasant.
Based on the above, I've concluded that traveling around the world with my family will bring me the most joy. Consequently, I'm confident that this is the right thing to do at this moment in my life.