By far, the one where you can do the best job and be most comfortable. The goal isn't to make as much money as possible but to enjoy your work. Nobody can go to a job they hate for years on end especially as the bank account grows and you can just walk away.
Affiliate marketing is the best way of making money online. Website which ask for a initial payment before geeting the job, most of them are fake! You can learn how to make money online with affiliation marketing for free here http://moneyonline.toptips.org
You will find a lot of interesting informations.
either one
the one you can do best
investment banking is shady
engineering is honest and true :)
wle