The decent part 1 and 2.
The first film is massively underrated for the budget they had for the film some jump scares and should of ended where a sequel could not happen as the second film just did not do it for me quite boring and was not needed.
The cave
This came out the same year as the decent and is almost just alike with minimal differences and with a few well know actors this should of been better than the decent as it didn't have known actors but the cave was just a B movie at best.
I always go back to these 3 films once in a while to watch mainly due to the fact there's not many caving films out there but in all the first decent is one to watch part 2 i would not bother and the same with the cave.