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?)

Cardano  or iota challenge eth? Is there a single project running on either project?
 

Currently eos and neo are leading the way as far as competition to eth but both have some major flaws.  Eos technically isn't even a blockchain, is very centralized and has lied about tps capabilities.

Neo is a blockchain but again is completely centralized and
Also doesn't offer real scalability.

My favorite platform project is SYSCOIN. it's silently building the best platform out there. There are currently multiple projects building on syscoin. Some major real world businesses are turning to syscoin go enhance their business model. Not just start up companies looking to raise millions in good but legit companies. The first company that chose to use syscoin is coinpaykents. They are the biggest crypto payment processor out there. Been around since 2013. They are very experienced in the crypto space. Could have chosen any platform to build on. They Chose syscoin for it's security, scalability, and INSTANT transactions.

Syscoin has been around since 2014. They got a massive team,  they are a publically traded company with major funding backing them. Silently the have built an amazing product. They didn't raise millions or billions in an ico, they don't spend all their money of marketing and type. They Chose to spend it on development. They are years ahead of most projects.

Take a look!!