What is the most *Fundamental* theory in physics?

[Arkadeep]

I want to ask that what should be considered the most fundamental in physics I.e. whether the Standard Model or Dimensional units or the fundamental forces?

 

[CWatters]

I think it's fair to say we haven't developed it yet...

http://en.wikipedia.org/wiki/Theory_of_everything

Finding a ToE is one of the major unsolved problems in physics.

Over the past few decades, a single explanatory framework, called "string theory", has emerged that may turn out to be the ultimate theory of the universe.