I'm happiest alone too, but I wouldn't be happy being alone one hundred percent of the time. For me the ideal would be to spend around two hours a days with others, and the other 22 hours of the day alone.
The one thing I can't do though is nothing. I can't think of anything more depressing, especially in an apartment. So, I bought a small ranch. This allows me to control who I interact with, it gives me plenty to do, and I also earn a little extra money to boot. The stillness and quiet are priceless--at least for me. I turn off my household appliances, and all I can hear is the blood rushing through my head and the birds singing.
Watching my cattle is particularly entertaining--and instructive. They are rugged individualists when compared with normal people:)