I cannot give instantly or suggestion about which is the best altcoin, It is actually, hard to distinguish on which altcoin that can stand long last like bitcoin did up to now. Though there are some coins are legit that they are helping bitcoin to promote it.
As you mentioned we could not really pinpoint which is the best altcoin as of now because there are lots laready of altcoins do exist today and there are some have good potential on following bitcoins path but still not sure. Back to the topic building a new coin would not be hard as long you have a good team of developer and a good road map for sure people would really use your coin but its not easy as it sounds because it would really need some new features compare to others so that other people would really shows interest to your coin.
