The Simplest interpretation of Quantum Mechanics is not even known well:
The Threshold Model.

It is the FIRST and simplest interpretation of quantum physics as proposed by Planck. Using Occam's razor, it would certainly win.

I like it because it is the simplest interpretation that still matches with all observations that I know of. It can also be tested well, and leaves room for adaption or expansion.

Because it is hard to find good information on it, I will explain it fully:

The threshold model (Plank, modified)

It places hidden variables in the detector. If the "energy" received at the detector reaches a certain threshold, the detector sees it as a quantum-change. The detector can be anything (even atoms), as long it stores the energy in some way. All particles can be treated as energy in this model.

Like the light that is received by an camera, energy needs to be enough to trigger the CCD-cell or CMOS-cell of the camera. The hidden variables are in the receiver, where it is unknown how much light each cell has received.

The starting conditions are kind of random or hidden. Plank dismissed his own model, because he thought that the starting condition was always zero. He did not take random start conditions in account. This logical correction is the only one needed to make it work and make it match with many observations.

Example:

Detector energy-levels before receiving 1 photon:    
00% 20% 40% 60% 10% 40% 90% 30% 20% 50%   
 Detector reads:
 0      0      0      0      0      0     0      0     0    0

After detection, light energy spreads over all positions:   
10% 30% 50% 70% 20% 50% 100% 40% 30% 60%
 Detector reads:
 0      0      0      0      0      0     1      0     0    0
                                               X
Photon found at X, where threshold level has been reached

Detector converts the energy to electric energy, 
This resets the cell again.

This interpretation makes some things a lot simpler. In antenna-technology, we can measure the phase of the incoming EM-waves. I think this mean that we are measuring parts of photons. Static EM-fields also become simple. We need no photons at all and certainly no virtual photons.

In QM we have to use non-existing virtual particles, to explain static fields. With this interpretation this is not necessary. Everything becomes simpler.

The interpretation does not need weird concepts like: multiple worlds, nor other dimensions, nor a conscious observer, no time-travel, no invisible pilot-waves. It brings energy back to waves that work exactly as EM-waves. The reason that we encounter particles, in this model, is because the particles are a result of a threshold that is reached.

The model can easily be expanded. Like different thresholds, resonating energy-waves, etc. But it already works well from the start. So for science, and using Occam's Razor, I propose to roll back all the weird theories that EM has produced, and start with thresholds first.

The theory is also completely testable, which brings the power of experiments back into science. In some experiments the detectors sometimes find 2 "particles", for only one being transmitted. Or sometimes no "particle" is detected. This is often ignored as noise, but it can also justify this very simple interpretation.

It is partially compatible with the zero-worlds interpretation (simplified MWI), but much easier to understand and use. Also similar to Pilot-wave interpretation, but with no particles.

Here is a website of a laboratory-scientist that is about this interpretation:
http://www.thresholdmodel.com/
He is not a good communicator at all, but shows some interesting experiments. But after reading my explanation, it is now a lot easier to understand his writings and talks.