1) Bradley Whitford: I can barely remember anything about Studio 60 on the Sunset Strip or his role on that show, but Whitford's Josh Lyman on The West Wing seemingly makes a welcome reappearance here as a pivotal character.
2) Anna Hutchison: Delphi's moved on from Underbelly, but still showing off what's Abovebelly, and pulling off a passable American accent at the same time. If you've seen any horror movies in your life it's not giving too much away to say you'll be trying to work out whether she'll be the first Girl to Go.
3) Shaggy: You mean that's not Shaggy from Scooby Doo as the fifth wheel stoner character?
4) Knowing what was going to happen to Thor on the motorbike: Can't watch, but can't turn away ...
5) Joss Whedon: the producer and co-writer. Yes, I know he's also responsible for Buffy and The Avengers - but did you know he co-wrote Toy Story? Whedon's wry sense of humour and his magic touch on his return to the horror genre are what make this movie so enjoyable. Plus keep an eye out for Fred from Angel.
Saying any more would spoil a bloody good movie, and a good bloody movie.
In fact, don't even read the back of the DVD case or watch the trailer, which gives away far too much.
All you need to enjoy this movie is a working knowledge of the horror genre. More specifically, the Cabin in the Woods genre. It's best if the rest is mystery.