I think a big part of it for me is escapism. Runescape is one of the games that did an amazing job at literally creating an entirely new world -- which also explains why I played so much World of Warcraft. It's a beautiful thing to be immersed in a medieval world with thousands of people who are similar to you and having the same experience right there with you.
I'd like to take credit for it, but it just wouldn't be right. You see, I'm an instructor at a world renowned special needs institute and one of my students (a severely mentally challenged 9 year old) wrote that in his journal today. I just wanted to share it with you.