Litecoin, I don't like it. It was a Bitcoin ripoff with no major value proposition, other than some people getting rich from the inflation of the crypto currency space. Charlie Lee is one of the big defenders of the current capacity limit in Bitcoin - probably because it makes his Litecoin more popular.

What's wrong with Ethereum?

IOTA, it's so far relatively unproven, they've made some weird technical design choices (like using trinary instead of binary, writing their own crypto algorithms from scratch, etc).

I haven't gotten through the whole whitepaper yet, but as far as I understand it every node needs to know the full history of all the coins they process, and every node needs to do proof-of-work, which I think doesn't sound much promising for a currency that's supposed to be used by embedded devices.

The concept doesn't sound much different from sharding, and sharding is on the roadmap both for BCH and ETH.

I haven't heard of the Bitcoin Cash security issue.