Turns out most of the really good ones are in the 'States, but if I get the chance I'd love to head down there and check some of them out. They look really spectacular!
Here's a link to the thirteen best haunted houses in the United States. Pay special attention to the ones in New Orleans: I was there a few years ago, and boy is it ever a creepy town. Beautiful, but creepy – especially at night time. All those old houses sitting in the middle of bayous...you can really see why Anne Rice decided to base the Vampire Chronicles there. You're half-expecting Lestat to leap out of the darkness and lunge for your throat any second – and in some of these haunted houses, that's just what happens!
Hope you enjoy it, and maybe I'll see some of you there this Halloween!