Bitcoin is compared to gold because of its price. Bitcoin remains gold with the highest price for one coin. Litecoin is still in use by many users but there are currencies like Ethereum that could match for silver.
In the world of cryptocurrencies there are more than one excellent currencies that could became a change for alternative paper money. Just like we have different paper money like Euro, Dollar, we have different kind of cryptocurrencies. Here are some list of the cryptocurrencies sorted by popularity in the world of cryptocurrency.
Bitcoin is the first cryptocurrency so it is logical that have the highest adoption rate. It is a payment method and you can buy almost anything with Bitcoin, so it is becoming good alternative to the fiat currencies, and it is completely legal.
One thing that is rising the internal value of Ethereum are smart contracts. Using the platform anyone can build projects, ideas, applications. This characteristic increase the users of Ethereum on daily level. Ethereum also have pretty strong community which is taking level up adoption rate of this platform.
One of the main characteristic of this cryptocurrency is that you can ensure cheap financial transaction in every possible ways. Ripple can considered replacement for fiat currency, very often it is used by the banks.
4. Monero, Dash, Zcash, Shadow coin...
This types of cryptocurrencies have high volume of exchanges and the adoption rates are so high that we could consider to pay for our groceries with these. But the most important factor is anonymity. These days where is everything tracked by government people called the Big Brother era, people learned to appreciate their privacy, and these three coins above mentioned are still the number one of anonymity providing.
Steem has very interesting concept in which every interaction between the two users for example likes, comments, posts are awarded. Network is rising, adoption rate is higher, who knows maybe in the recent future this would be alternative to social networks like Facebook and Twitter.
To make a resume, there is more than a couple currencies that can be alternative to the fiat currencies. The only thing we can do is to wait and see which one will prevail.