Hmmm... Hard for me to say who I'd like to see come back, since major incidents (arguments and controversies) almost always seem to happen whenever I go more than 2 days without logging in. People always seemed to get banned during times when I'm away (out of the country or otherwise not in a place/position from which I can log-in), so half the time I don't know who got banned or why-- not that most of us regular posters (those of us who are not mods or staff) ever find out exactly why most people who got banned either temporarily or permanently ever get an explanation for it. I only sometimes find out later when others mention it if someone was banned or not.
For example, I was away in Finland when Westside got banned. I was there for nearly a week, and when I came back, Westside was gone. The situation and the fallout from it all happened while I was away, so to this day I haven't a clue at all what happened or why it led to him receiving a permanent ban. It was probably another few days after I was back that I even found out he was gone.
I guess I would have to say Elle/Alana. She was a really nice and frequent poster. I'd met her once, and she really offers a great service, and the situation that led to her being banned (one of the few cases where I knew the background story that led to it) was really unfortunate.