Superconduction and superfluity are examples of macroscopic quantum phenomena. I’m not sure they can be classified as entanglement, but the fundamental reason is at least as weird as entanglement and I think they would be also very difficult to simulate.

There is also a correction of the law for Ideal gases. It’s more important when the temperature is low and the quantum effects are more visible. Essentially, let’s suppose that you have a lot (~1E23) of identical atoms/molecules in a gas. In some gases the atoms/molecules can’t be in the some quantum state at the same place (fermions) and in other gases they can be (bosons). Moreover, the particles are all identical, so you can’t label them and can’t track them. This causes an “apparent repulsion” in the fermions gasses and an “apparent traction”. It’s not a real force, it’s only a statistical effect that looks like a attraction/repulsion. (It’s a little more complicated because the positions and velocities are not discrete, so “the same place” is more difficult to define.) (I can’t find a link to a direct simple measurement.) More info: http://en.wikipedia.org/wiki/Fermi_gas and http://en.wikipedia.org/wiki/Bose_gas