Altcoins can differ from Bitcoin in a range of ways. Some have a different economic model or a different coin-distribution method, like altcoins that were given away to all citizens of a country. Others employ different proof-of-work mining algorithms, perhaps to resist specialized mining hardware — or maybe they don’t even rely on proof of work at all. Several altcoins offer a more versatile programming language to build applications on top of, while yet others offer more privacy compared to Bitcoin. And there are also altcoins that serve very specific, non-monetary use cases, like domain name registry or data storage pointers.
As far as distribution method goes, the only fair distribution model is no premine, no developers fees, equal start for everyone. Like in bitcoin.
As far as proof of work algo goes, they can all become prone to specialized hardware (ASIC). The ones that are resistant to ASIC, are probably not widespread enough and therefore not lucrative enough to use specialized hardware.
As far as programming language goes, the altcoins developers should be very careful not to create security risks with their versatility.
Given all this, I don't see any altcoin that is going to rock this year.
