I think katanga canyon is good at the moment, a family flat would be a great addition though.
Duel is really good IMO, but could be much better (if the effects actually worked), I think if it was all working, it would be a world class dark ride. I do like going round without the blazers, but I also love it when I absolutely obliterate my friends score (every time). I never went in the haunted house, so I can't compare it, and I don't know how good it could be, but IMO, it is a quality ride.
In this thread, we seem to be forgetting another ride that I don't believe has long left, enterprise. We keep saying that blade and ripsaw will go soon, but (to a slightly lesser extent) enterprise is In danger of being removed. It is down most days, and very rarely makes it though a day without a breakdown.