For sunset photography we recommend either Hopi Point or Powell Points but both tend to get quite crowded as they are very popular. Make sure you arrive at least an hour before sunset to secure your spot as there are many photographers with tripods and once they have their cameras ready, you won't be able to "squeeze" in between them. Tripods for sunset photography are a necessity as you won't be able to hold your camera for longer exposures without shaking. For photos of the sunset we used Lee ND and Graduated Filters.
If you feel like you can use some exercise, we recommend walking to Hopi Point along the rim from the Bright Angel Lodge. We even managed to spot an endangered Bald Headed Condor resting on the rocks. When we took a picture, we noticed they have large numbers sprayed on their side.