OP my stereotype hippie thinks too much, therefor not so happy as rather concerned for our future.
Id say happiest for me would be drunkard religious folk. They are happy now cause they are drunk and are smug because they are always looking forward to the pearly gates of heaven where another bottle of wine awaits.
While high, definitely the E-tards. That big grin on their face, smiling so much their cheeks hurt, telling everybody and their mother they love em. Until the crash comes after a long binge... Then they are probably the saddest people around lol. (Spoken from a ~30 day E binge back in 2009)
I thiink drinkers are the 'happiest'. Not sure what you really mean about happy but ive been around alot of social groups and last year when i was hanging around some of my drinking buddies (3-4 times a week heavy drinking) i gotta say they were the 'coolest' and most fun to be around. Not just when drinking when sober too.