Right now people say that trading is the most profitable source of income in bitcoins. You were just needed to buy and hold and you get the profit.
Trading is and will be potentally the best way to get few btcs.
But a signature campaign and any other bitcoin affiliate programs are the most save and reliable. Ofcourse you participation on the forum is limited. After some time, the amount of subject you had already participated grows, so you have not much more to add.
Playing some faucet games do not have to such issues like the above two. You are never burned out, and you never need to be lucky.
Right now there are only few games that are not terribly boring. They are:
http://www.satoshigalaxy.com/?r=przemaxThe game gives you the options to have a semi passive income from owning the colonized planets
The other is:
https://bitfootball.net/index.php?r=17h8ZEmFae6TCVV2RSMSNKRyTYjMYJauHxTop players get 100k satoshi a week.
Soon there will be a dragon knight of valeria 2 as well. Its not as good, but worth to play a bit.