Beijing's Yong He Lama Temple (雍和宫) is constantly beckoning. We live a short bike ride from it, and it's visible from our apartment's balcony. Whenever we have guests, we take them to the Lama Temple. They're never disappointed.
The compound has over 300 years of history, with many prayer halls and works of art to enjoy. The highlight of the Temple is the giant Buddha statue, carved from a single piece of sandalwood.
Across the road from the Lama Temple is the Confucius Temple (孔庙). It's is older than the Lama Temple, and it's not quite as touristy. I've only visited once, with my mom and Katie. We got lucky when we were treated to a lovely dance performance, and we got to see kids working on their calligraphy skills.
If you come to Beijing, you should add a visit to the Lama and Confucius Temples to your itinerary. You'll only need a couple hours to see both, so they're well-worth a visit.
You can see more of my photos from the temples here, here and here.