You have the most common shot which can be taken facing the front of the Taj Mahal, but it is an angle done to death. Mehtab Bagh is a good place for some awesome photos, specially during sunrise. You can get lovely pictures of the Taj Mahal during sunset from across the Yamuna River, or if you take a Yamuna River boat tour. Paradise Park is another great spot to capture the structure, specially during sunrise. Inside the complex, any angle would give you a better picture if you capture people for a sense of scale in it as well. Additionally, the Pietra Dura is an interesting spot to click photos. You can get some great shots in the structures to left and right of the Taj Mahal. The one to the left is an operating mosque that you can visit.