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?)
NEO is a competitor that can compete and defeat Ethereum. NEO has its foundation and ecosystem that supports any tokens that want to grow on its basis. The NEO platform was chosen to develop tokens of multiple projections, and this helped its price rise to compete with Ethereum.