I’ve always been a fan of the djangoproject.org and it’s what I use for my web server at home: www.peteware.com
But the coolest news is that Google App Engine is based on it. Here’s some info:

For me, Django provides a great object to relational mapping interface combined with a wonderfully clean seperation between business logic (a view in the django world) and presentation (a very nice templating language). Each piece is wonderfully independent from the others.