All projects are interesting in their own way, but not all projects are successful. Today PolkaDot is successful and a large number of people gather around this project. And where there are more people there and more money.
If you are confused about buying coins then you can see from the supply, the project developed and the trading volume at the exchange, because all cryptocurrency prices depend on these 3 factors, in my opinion Polkadot and Cardano can be the right choice to buy.
What the factors? Polkadot and Ada real flagmans, but you forget about the bull market, he is still going up. I think right now the simple egg will shot and the Civic its not so bad (look to the graph).