I would say Python. why you may ask? For the following reasons:
1. A wide collection of web frameworks from which you can choose from, e.g Django, webpy,turbogears, web2py, karrigel the list goes on.
2. If you are so inclined, you can roll your own framework the help of WSGI.
3. Python as a language is very simple and for an experience programmer, you can be up and running within a week.
4. The python community is huge and helpful, with a lot of books and documentation.
Just my 2 cents anyway.
Although Python has been leaping down the slippery slope as well, I think calling Ruby's syntax simple is a bit of a stretch. Ruby has many--intentionally--more ways to do everything, and some of those more ways have small gotchas built in.
