Okay.. This is stupid.
This should be the first thing you learn when starting to go into the hacking mindset: For every scenario there is a ton of ways to attack something. And you should be able to think up most of them without blinking, at least the outlines.
A target doesn't have one attack vector, it has a bunch. And not only technical, and not only direct vectors but indirect attack vectors as well. Depending on how blackhat/unethical you are, it will have an even bigger attack surface.
This topic might help to shed some light on things.
http://evilzone.org/tutorials/hacking-start-to-finish-(quick-list)It dosent matter if you are attacking a email account or a game server. The different attack vectors can be applied to both. General idea is: Get access to any parts of the system or a system that has access to the system or yet another system that may or may not have access to THE system or yet another system that [...]. Where a system can be, a lot of things: A person, a computer, a access point, a document, other hardware or something else that will help you gain the information you need. Then you work your way up from there.