I've taken hard looks at pretty much all of them, and it really came down to Ruby or Python. I've been using PHP for about 7 years now and have a couple experience levels in Java and C/C++. One big thing I want to do is de-couple myself from "web programming". While PHP can be run from the command line or in a stand alone environment, this is really little more than a novelty. Everyone knows that PHP apps are web apps.
There are actually a ton of resources online comparing Python and Ruby. One example Google link: here
I'm extremely fastidious and a total type-A, so thinking about things like forcing developers to use specific whitespace conventions and explicitly mentioning self inside classes and such actually pushes extra blood into my corpus cavernosum. Also, there just seems to be less out there about Ruby. Less packages, less job opportunities on the side, etc.
I also couldn't quickly find anything that would compile Ruby code into a standalone .exe, but I'm sure there's something out there. I already know there is for Python, which is kind of what started this whole thing.
The nice thing is that I'm not coming from an older Python background, so I don't have to unlearn old ways of doing things. I'm starting with Python 2.0 and so deprecated orpreviously-broke-but-now-fixed stuff isn't going to be a factor for me, for instance many of the warts mentioned in the link jim crawford provided (which was a good link, BTW, and I appreciate it).
Thanks for the replies and book recommendations, all. Keep 'em coming if there are more. I can think of a few people who haven't posted yet who are Python fans.