Torvalds is probably the programmer's programmer.

But I at least want special mention for Margaret Hamilton whose work quit literally put someone on the moon. Just read how sophisticated the program was here: http://en.wikipedia.org/wiki/Margaret_Hamilton_(scientist)#Apollo_11

Among her career highlights:

• Wrote the program controlling 'The Eagle' that landed Neil Armstrong on The Moon.

Included quite sophisticated priority and load management rules within a cooperative multitasking protocol in a tiny amount of hardware.
Based on her account it is reasonable to accept that without that sophistication the landing would have aborted and there would have been no landing (in that mission) 1969.

• Is credited with coining the term 'software engineer'
• A pioneer of asynchronous software

Still (in my view) the most challenging area of computing.

I think my wish to include her is precisely that point about software engineer and asynchronous software.
I think before her (and without disrespect including Knuth) computer programming was (and to an extent remains) a branch of mathematics.
However a flight control system for a spacecraft clearly moves programming into a different paradigm .

As stated at the top of my answer I am proposing honourable mention for Hamilton. That is on the basis that she was a real pioneer of the arts and disciplines that made this question even meaningful.