The Conjuring
I like how the movie plays like a procedural and actually opens with a B case, in which they will quickly resolve before the end of the opening sequence.
A Haunting in Venice
This is a very traditional whodunnit, with the usual suspects of affluent family members, their acquaintances and the help all trapped in a building while the great detective slowly grills each person until the reveal of the murderer(s?) is done in a grandstanding fashion.