The GIANTS of Computability

I never read the original paper from A. Turing, where he defines Turing Machines.
But that paper was published in 1936 and it is freely available, and so are many other texts from the founding fathers of computer science.
And many of these texts are quite readable and surprisingly modern.

Check them out:
- ON COMPUTABLE NUMBERS, WITH AN APPLICATION TO THE
ENTSCHEIDUNGSPROBLEM By A. M. Turing [article]
- Automata studies Edited by C.E. Shannon & J. McCarthy [book] (check out the authors of this AMAZING book!)
- List of important publications in computer science [link]