Right now the perceived big 3 are:
BTC, ETH and LTC. Obviously from a Market cap perspective those aren't the Top 3 but again, that's why I used the word perceived.
That's fair enough. To add more to your post I'd say that by looking at the Market cap I'd consider BTC and ETH obviously as the main 2 coins and with runner ups of Stellar & Tether as to me they look like 2 most stable coins.