It seems that most new ICO projects are being built using ETHEREUM or ERC20 Tokens. Bicoins is still the big daady though, and in terms of potential monetary gains, BTC is still the leader. This may change or it may contine, each of us must decide how to invest.
This was an educational video to watch, sources would have been a good addition though. BTW everyone should have a look at the blockchain website, there is a lot to read/digest, and it doesn't seem good for the original Bitcoin, and they're definitely about making money as a business.
STEEM seems a logical choice with so many use applications already, Steemit, Busy, ChainBB, Steepshot, Dmania, DTube, DLive, DSound, Zappl... and more all using STEEM in some way on their app. If you invest in other tokens, at least keep some STEEM, it will be big.