Lineage II, but my experiences with it sort of cemented my feelings on non-consensual PvP. Suffice it to say that it involved someone who had set herself up a little sniping-hole from which she would murder any and all low-level characters with an arrow through the neck. As she explained in the area chat, this wasn't for rewards or anything. She was doing it because she found it funny.
Lots of of people do find that fun. But I'm personally not keen on that as a motivational technique. I don't want to level up so I can be one of the bullies instead of the bullied; I'd rather just opt out.
Why did I tell you that story to lead off Ask Massively? As Bill Cosby would put it, I told you that story so I could tell you this one, or at least so I could answer one of this week's questions about Lineage II. Also, thermodynamics. If you've got a question for a future installment, you can leave it in the comment field or mail it along to firstname.lastname@example.org.