I have used many editors in the past, either under Windows or OS X. Too many, I have really lost the count. The last one I used was Sublime Text. Great editor, cross platform too, but pricey. Each time I would get the nag, I would feel guilty for not buying me a licensed copy.
I tried Atom when it first came out. It was buggy and slow, really, really slow. Not anymore. I am using version
1.0.9 now, and it is a joy. So fast, so customizable, so complete, so free!