Music, good food, honest compliments, good humour, the sun, cute animals (except the stingy and bitey types), nature, summer rains, drawing, the smell of freshly cut grass, comics, talking with long-term acquaintances, video games, a good nights sleep, achieving my set goals in life, daydreaming and so forth.
...Funny how this thread lives on, even if it was started off by a spam-bot, don'tcha think?
If we are going for instant 'happiness' then obviously drugs, but if we are thinking more long term here then exercise, music, and the few friends I have.