Reverse Stuff:
https://www.hacking-lab.com/index.html
http://io.smashthestack.org:84/
http://www.flare-on.com/
http://cryptopals.com/
https://microcorruption.com/login
https://www.hacking-lab.com/index.html
http://wargame.nuitduhack.com/
http://overthewire.org/wargames/
http://crackmes.de/
http://www.root-me.org/
http://www.binary-auditing.com/
OSCP:
Post Exploitation List
OSCP Goldmine List
Articles:
Pentester Articles I