Django's template system is the sexiest I've seen (mostly because of the simple syntax and inheritance). I've been meaning to check out web.py for a while now, will have to see how web.py templating compares.
{% %} {{ }}
Also, it's bizarre to use a language (Python) that uses indentation instead of endif's, closing braces, etc., and then turn around and require endif's and endfor's in your templating system. web.py's templates get that right: just use the Python style.
{% block title %}{{ section.title }}{% endblock %}