Grand Canyon Tours
On my first visit to the Grand Canyon many years ago, I saw those rafts going down the Colorado and decided that one day I'll do this too. This year it finally happened, and it was worthwhile, though I wish I'd done it 10 or 20 years younger, when the camping part of the trip (mainly sleeping on a pretty hard cot) might have been less uncomfortable. From a fitness point of view, I would not recommend participation if you cannot climb on a chair by yourself, ideally without hands - but even if you can't, the guides will help you by dragging you up to the rig etc. (we had one person who required this type of assistance).
The experience was great, I never felt unsafe, the tour guides were friendly and resourceful, food was plenty and tasty, and the landscape is just amazing (and that's why you do this trip, right?).
Western River Expeditions made sure I knew what to bring - they sent me a myriad of preparation emails with lists, links to videos and what not, so there were no surprises in this regard.