Can I get Notepad++-style vertical selection with arrow keys in Sublime or Atom?
Solution 1:
Sublime Text has this feature in built and it's called Column Selection functionality. It's super simple: Ctrl+Shift+↑/↓
Or, if you have a middle mouse button, just middle click and drag (in Windows and macOS).
Documentation
Solution 2:
In Atom, you can install the multi-cursor which works exactly like Notepad++.
I'm not sure about Sublime Text, but take a look at the MarkAndMove or PowerCursor packages.