I love seeing natural made places because of water and weather, and Antelope Canyon looks like a great photo op. I've seen images and I bet those images don't do it justice. Is it worth visiting Antelope Canyon at least once?
It is a pretty cool spot! I have only gone once. Just make sure you get a good guide as you can run into some dangerous wildlife when moving through it. I would wear boots for this reason.
I have never been but know several people who have gone and say it is worth it. My one friend said that it is basically an example of nature's covered canvas, i.e. it is a work of art done entirely by nature.
It is a pretty place. I think a lot of the trails and scenic tours are worth it if you have never been on any. I would put this at the top of the list though, easily in the top 5.