I prefer coinmarketcap. Coingecko is just inconvenient for me, I didn't understand this web-site, while coinmarketcap has a very clear interface so I understood how to use it and where to find all the information needed. First of all, there is a table of top-100 that I use to find fundamental projects. Secondly, there is a lot of useful information about supply, exchanges where this coin is traded etc.