RAW processing software,.....Which is the SIMPLEST program?

Personally, I don't particularly like Adobe's approach to RAW processing, I much prefer DxO Optics Pro, even with its rather quirky (but very intuitive) interface.  DxO produces a far finer noise pattern than Sony's "blocky" in-camera JPEG engine.  The main advantage of DxO is the large database of camera and lens combinations that it supports for automatic distortion correction.  This used to be limited to a small number of Sony and Minolta lenses, but since v7.5 many third party lenses are also supported.  It is a bit pricey though...