If one was to clone an altcoin code base to start a new coin, which one is the 'best' besides Bitcoin 0.13.0? Which one has the best features and best security?
Your criteria is very hard for anyone to discuss in a forum. When you say "best features" what do you really need for your "coin" to do? Also for "best security" it would also mean that you have to convince miners to mine your coin and get enough hashing power to secure it.
Please make your question more clear and please tell us what you want to achieve so that we can make good suggestions.