Color performance in bright conditions was very good from all of the phones. The detail, exposure, and color seem best from the HTC One X, but the differences are negligible. The Galaxy S3 appears slightly overexposed, but I'm not sure most people would notice.
From left are photos from the iPhone 5, One X, and Galaxy S3. The One X's low-light shots tended to have a magenta hue to them, but sharpness and detail were good. The iPhone produced warmer tones, whereas the Galaxy went whiter. They all have issues, and really what it comes down to is preference.
While the One X was a bit disappointing in the previous slide, it made up for it when I shot food (middle). There's still slight problem with color, but it's close to what I actually saw and there is a good amount of fine detail, especially considering it used ISO 1000. However, the iPhone 5 (top) edges it out with better color. The Galaxy S3 is good, but the food looks flat in comparison.
The iPhone 5 also produced better fine details in low light, but part of the reason for that is it used a lower sensitivity of ISO 500, compared with ISO 1000 from the One X and the Galaxy S3's ISO 800.
All three of the phones were very good at shooting close-ups. These are 100 percent crops of the inset images. The only issue I had was with the focus on the One X (middle), which seems to have focused just above where I tapped. However, that might have just been user error.