I tend to go to python, just because it's more likely to be pre-installed on any system I work on. I enjoy ruby but it's not my goto because it's not likely to be installed for some reason.

subprocess does have a lot of boilerplate you have to use to be able to use it for simple tasks, but the flipside of that is that it's more flexible than any other shell callout syntax. You can easily feed stuff to stdin and read stuff from stdout and stderr all in the same subprocess call, which, in other languages, requires a lot of fiddling and usually some extra libraries.