There’s a definite desire among music software developers to make their products easier to use, but even in that context, Sampleson’s free Push synth plugin is an extreme example. Its main interface comprises just a single button: simply press it to generate a new sound.
Behind the scenes, this is a subtractive synth; pressing the button randomises the parameters, giving you a different patch. You can either use this sound as it comes, or tweak it by clicking the Edit Current button, which gives you access to some hidden controls. Patches that you like can be saved and shared.
Push can be downloaded for free from the Sampleson website. It runs on PC and Mac in VST/AU formats, and can also be used standalone.