Ruby did/does have a nice OOP approach. I remember when Python and Ruby were first kind of being touted as alternatives to Perl, and Ruby always seemed more well-thought out to me--the Python 2-3 split was something I sort of saw coming.

I wouldn't say I'm a functional purist (at least so far), but inheritance in particular has caused me some headaches in the past. I like Rust's approach to all of that, but it's much lower level.

Honestly, if Crystal ended up taking over the programming world, I wouldn't mind. Its a very nice language with a lot of advantages over what people are using now.