Dom Dunc wrote:
Single room thrillers are one of my favourite sub-genres.
I'll agree with CUBE, definitely one of the best but I've never bothered with the sequels so can't comment on their quality.
EXAM was a recent one with some good ideas, even if it did seem stretched to fill the running time.
The Spanish film FERMAT'S ROOM is also worth checking out, especially if you like puzzles

I'll also add ALTITUDE from last year. A lot of people hated that movie iirc but I quite dug it. A unique take on the single room theme.
I actually saw
Hypercube (Cube 2) before the first and really enjoyed it. I even liked
Cube 0 the prequel - all pretty nifty low budget thrillers that play on a similar theme, but with acceptable (and fairly predictable) outcomes.
Exam was a very good low budget thriller too and I agree it ran out of steam towards the end and spread itself a little thin (bit too
Sawesque in it's denouement I thought.)
Fermat's Room was another great little low-budget film. I watched that around the same time as
Timecrimes - a great Spanish double bill there.
And I have to agree with
Altitude. It was on at the Frightfest all-nighter and I felt like I was one of the few people who genuinely enjoyed it. A nice Lovecraft/Outer Limits/ Twilight Zone feel to it. Not ground breaking, but it did what it did well I thought.