I decided to visit the Dungeon on my week long trip to London as I wanted to pack in as much as I could, I have to say I wasn't expecting too much, but I was very pleasantly surprised. First of all, if you plan well, and get 2 for 1 Merlin Entertainment vouchers (available all the time on cereal boxes/ newspapers/E-Bay etc - you just need to keep your eyes open) you get the best from your visit. I never leave home without them.
I visited on a week day during term time, and walked straight in, although there was about a 20 minute queue inside - this is London, you also queue for the free museums. I found the experience very entertaining, and informative. I'm not much of a screamer, but I think the people saying it wasn't even scary are sort of missing the point, it's a walk through the gory history of our capital, not just a 'make you jump' scarefest - for that, go on a ghost train. In my opinion, the actors were very convincing, engaging, and involving, as they drew the audience into the plot, accusing us of being accomplices in various crimes, obviously they were a bit over the top, but they do have to entertain the kids too, and they seemed to enjoy their roles.
Along with the acting scenes and the history, which is also on wall plaques dotted around the place - I don't understand one contributor who said the plaques are in English - you're in England, what language do you expect? It would have been far too much if every language on earth was up on the walls. There are also rides, one a wet one, we sat at the back of the boat and got a bit wet, at least it was roasting hot outside. Some of the exhibits and scenarios make you jump, and some are quite funny (the autopsy room springs to mind, where we were squirted with a full bladder), but all were informative, and I loved it, maybe it's a Marmite attraction, but I do like to try things for myself before making judgement.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.