Nano, OMG, Stellar are all good products. But credits has the potential to eclipse all of them.
As for PIVX, it is simply better than LTC in every way except brand recognition. PIVX has 1.3 second transactions, the most advanced and efficient implementation of zerocoin privacy protocol. 10% of the block reward goes to a treasury to fund PIVX related projects. They have an upcoming decentralized exchange. They are the first o do many of the privacy innovations in privacy tech like first PoS zerocoin, first mobile minting of zPIV and many more. Just check http://pivx.org