The closest to this I found is Org Mode in Emacs. Pros and cons:
+ it's free
+ it's a flat, text format, human-readable and editable even outside Org Mode
+ has one of the best table editors ever
+ off-line first, no cloud bullshit
+ can handle source code and images pretty well
+ awesome export options - including LaTeX, HTML and nicely formatted UTF-8 plaintext
+ infinite flexibility of Emacs
- infinite flexibility of Emacs
- not Markdown (for those who care)
- you have to do sync yourself (I do with Dropbox)
- limited support for mobile (Orgzly is OK and works w/ Dropbox sync, but very limited
functionality compared to what Org Mode in Emacs provides)