At my place, and on my brother's forum, I prefer to be an admin. If someone has a problem, I like being able to help them whatever way I can. But, when I am anywhere else, I prefer to be a User. When I am on someone else's forum, I look at it a lot like being on vacation.. and of course, the last thing anyone wants to do is work on their vacation. I like being able to kick back and relax with the other members, and let someone else deal with the problems drama of running a forum.
I have turned down many, many, MANY offers from admins asking me if I'd like to be a mod or admin.. simply because they like the way I run my forum, have it set up and the way I do things on it. My thing is, I don't mind giving them a few suggestions, or leaving input when asked, but that is about it.