EVE Online - The best way to make a lot of money in a long game strategy, is to get high up in an Alliance so you have access to the Alliance's wallet and ship hangar, then just one day steal everything and disappear.
Or pretend to be helping someone out on a mission, don't have a loadout for NPC killing, but instead have one for player killing and just gank the **** out of your "friend".
Also espionage is a huge thing.
However, you can get really far being a nice guy and trying to make people work together, for example Shaun Smith, aka Vile Rat, aka one of the guys who was killed in the US Embassy attack two years ago.