I think there are a few that are already known, but I am thinking also new coins with crazy potential.
For me, there is one coin targeting mass adoption the right way, meaning easy integration as a payment option(imagine adding few code line to your store and there you have it), mining available for anyone, no installs, no downloads, wallets created automatically, easily exported/imported to/from any USB flash or hard disk, possibility to create a new mining pool with just one click, all intended to be as simple and light as possible for the end user.

Above all that, add token options, smart contracts, a optional degree of anonymity, scalable tx/sec, all code public, written in JavaScript from scratch. I think this coin will be quite big in the future, you should give it a look( webdollar ) : https://bitcointalk.org/index.php?topic=3257668.0