This is a very interesting topic. Money does not buy happiness but it does buy opportunities. Time and again, the research shows that experiences and relationships are the key to happiness. That said, if you are slaving away all the time, it is not possible to have either. I think the key is to have a job that pays enough for you to improve your relationships through experiences. Doctors and lawyers get paid a lot but they are never home. School teachers don't get paid much but they get summers and all holidays off. I have several friends that are orthodontists and dentists and they get Fridays and weekends off and work normal business hours Monday through Thursday. One of my friends lives in Wake Forest, NC and one of the "happiest" guys in town is this orthodontist - http://gladwellorthodontics.com/meet-dr-gladwell/. From my understanding, he worked his rear end off in his 20s and 30s to now be the big guy in town which allows him to travel, buy nice things and enjoy his life.
TL;DR - Become a dentist or orthodontist. You get Fridays and weekends off and make good money.
“Some parents let their young kids win at games, but mine never did. I don't think it was because they were particularly competitive, they just wanted to teach me a valuable lesson. Life is mostly just learning how to lose.”