Which are the best competitors to Ethereum, and why do you think so?
(I know on top of my head that Cardano and IOTA try to challenge Ethereum,
although they still haven't proved much from my understanding?)
Not only Cardano and IOTA, but also NEO (known as the chinese Ethereum), Universa and EOS.
Some of them are available to invest on
CoinBundle, if they are on the list of best 20 cryptocurrencies.
Universa is very new, while NEO and EOS are stable.