One of my favorite parts about Paris is the way the city lights up at night. The eiffel tower sparkles on the hour every hour. Its beautiful in person and for as many times as I have seen it, it never gets old. To view the eiffel tower at night there is a great view from the top of the Arc de Triumph. Make sure to bring a coat and possibly gloves. It gets cold at night.
or you can visit the base of the eiffel tower at night for an up close view