The HTC One X looks better and has a better camera but it doesn't have a removable battery or SD slot. Also it's made by HTC.
Samsung cameras have superior white balance and more natural color production. HTC tend to oversaturate colors, which can be amazing or bad depending on what you're shooting. Both Cameras are hugely configurable, though, but most smartphone users don't want to have to fiddle with half a dozen settings all the time to get a great picture. So I'd choose the GS3 over the One X even for the camera since the default picture quality is more natural and better white balance, and the Video+Audio recording on the Samsung is clearly superior (the latter being what I most use my smartphone for, for home video analysis).
HTC isn't really known for high quality these days, BTW, that was the whole point of the One Series, and they took a bunch of shortcuts with that device (some of which you mentioned) to achieve that
The lack of an SD slot is a deal breaker in the US for many people given it's only available as a 16GB variant. It also has half the RAM of the S3, which has a 64GB SDXHC slot in it. The screen is better for some people, but for multi-media I prefer the GS3 screen's punchier colors (color temerature is configurable in TW Nature UX, BTW). The AMOLED screen is more battery efficient than the LCD, and the GS3 has a factorably larger battery than the One X - and it's removeable.
TouchWiz has more value in it's bloat than Sense does, which is a complete turn-around from, say, two years ago.
The S3 is easily the superior phone, especially since even between the cameras there isn't so much to choose between the two. The biggest difference are more in the software, IMO, which is superior on HTC phones (like Half Speed 720p), but Samsung is no longer far behind even in that area. Samsung's phone produces much better video than the HTC, especially when you factor in the sound quality in the video. Another thing I like about Samsung is that often their camera firmware is updateable independently of their smartphone software FW (and not subject to carrier approval). My Vibrant got like 3 camera FW updates when I owned it. Not sure if the GS2 or 3 is set up similarly...
HTC has always had white balance issues in their cameras, I dunno what the issue is but they keep making this mistake. But even the One X has the Yellow Tint issue phones like the Vivid and Amaze 4G (and Rezound) exhibit (mostly in lower light conditions - i.e. not outside on a sunny day where they took amazing images). It's as if they put a Yellow Backlight in their Camera Sensor so when the backlight is ramped up in lower lighting it tints the entire image yellow (which, admittedly, is better than the Pink/Purple/Fuschia they were known for in the past). They also continue to treat video (especially the sound in the video) like second class citizens
You get better 1080p Video+Sound out of a Galaxy S2 (nevermind a GS3) than out of a One Series device. At least it's better than the Vivid/Amaze4G/Rezound, though, which was so bad you pretty much had no choice but to turn sound recording off (and they only recorded in Mono).
Screen Cap from a video taken with HTC One X in lower light indoor conditions (an Ice Rink):
That's just not acceptable white balance in the camcorder. The Ice is White. Use that as your frame of reference.