As there’s already a strong blockchain providing the value-transferring mechanism there is no need for “altcoins” (forks/copies of Bitcoin) to try to take that same role. Taking a look at the top 100 cryptocurrencies at Coinmarketcap there are few coins that actually provide another useful mechanism. One of them is Namecoin, providing a great blockchain-backed solution for domain names. But most other coins try to chase the holy grail function that Bitcoin already serves (and most of those founders are trying to get rich quick).
Ether, after changing course, is now more targeted towards paying for computation/bandwidth/storage. In the beginning people behind Ethereum were arguing against Bitcoin. They don’t do that anymore, now instead calling ether complimentary to bitcoins. Smart move. However, in a perfect world the price of ether should dive down to the actual cost of paying for computational resources – i.e – there’ll be no speculation in the ether currency.
There are also funny coins (like Unobtanium) and coins that totally miss the point of Bitcoin trying to peg a cryptocurrency to a real-world commodity (like Uricoin and Solarcoin). But so far I see no coins a part from Bitcoin and Namecoin that actually fulfill their promise to provide a unique valuable mechanism. Dash is probably the top contender for a more “anonymous” coin, we’ll see how much the public values that property. But there’ll probably be add-ons to the Bitcoin network providing the same mechanism (shapeshifting done right for instance).
Ripple is not decentralized, Ethereum is not decentralized. They may work for certain actors and certain applications, but stand no chance against Bitcoin (for value-transferring) in the long run as a fully decentralized currency is more valuable than ones that aren’t.