<p>which would you recommend?
which is faster, reliable?
apache mod_python or nginx/lighttpd FastCGI?</p>

Personally I've had it working with FastCGI for some time now (6 months or so) and the response times 'seem' quicker when loading a page that way vs mod___python. The critical reason for me though is that I couldn't see an obvious way to do multiple sites from the same apache / mod_python install whereas FastCGI was a relative no-brainer.
I've not conducted any particularly thorough experiments though :-)
[Edit]
Speaking from experience though, setting up FastCGI can be a bit of a pain the first time around. I keep meaning to write a guide..!