You can go through visit this page
www.coinmarketcap.com for reference and you can find top Altcoins and some other good coins listed.
It's one of the most trusted source of Cryptocurrency ranking and you can find almost compete information.
Yes, since there are so many different crypto coins, this website is very good for finding basic information about them, Also, you can use mytoken APP to see details, you can download it from mytoken.io.