Well, I fucking hate whole France, so saying Rome beats Paris was maybe a little too easy from me.
The churches in Rome are great, espescially the Jezuit (sp) ones. Try to visit the Il Gesu church, it has a little scene built in the wall with a fountain, and if you toss in a coin the scene moves and you hear wack music, Catholics are so childish sometimes.
Also nice is the San Clemente church, from a historical point of view that is, it's three churches built on top of each other (like so many other churches), but the two below are excavated and you can visit them.