Bitcoin, in my opinion is a proven warrior. It has survived all the blows coming towards it since day one. Now that the price is much lower, I do consider it a good buy. Being said that, I also consider ETH a good buy option too speaking from the little experience I have because altcoins tend to move more than bitcoin. Therefore they are a good source of profit. But as I said, bitcoin is like an invincible warrior in the crypto industry. So I think you should rather buy bitcoin now.