You can analyze a coin like a traditional investment. Look at the fundamentals and the technical situation. There are so many methods if you want to do this but at the moment it does not matter a lot because the cryptocurrency market is still very young. So how do you determine if a coin is any good? What is it really worth?
I think one the best indicators to know if a coin is worthy to invest in, is to look at the fact it is being used or not. Take Steem for example.
Steem has a lot of issues. We all know them. But in the end, Steem has value for me. Why? Because I use it every day. Is there any other coin I use everyday or even weekly? No. So for me, Steem has got a lot of value and it still has room for a lot more potential.
A good website I regularly check is https://blocktivity.info
Here you can check how much activity the top blockchains have which is probably the best indicator of value.