Ronald McDonald House Charities.
Imagine your kid is sick, and needs to be in the hospital for an extended period of time (or even just 2 nights). Imagine that said hospital is 45 minutes away, or 450 miles away. What are you, mom/dad going to do? You want to stay with them, but you can sleep in a chair at the hospital, or get a hotel room at $60-$200 a night... That is either uncomfortable, or expensive.
Enter Ronald McDonald House. Free room for mom and dad and siblings. Meals are provided. So are snacks. Living rooms in the place. Laundry facilities, including detergent. Volunteers cooking for you. Truly a godsend. When I first got into the room with my parents (my daughter was in the hospital across the street, my wife stayed with her), I just started weeping out of gratitude. They ask that you contribute $10 a night. We did. Afterwards we donated a lot more, because we were able, but they don't require any donation and there is no judgement whatsoever.
They'll forever be my favorite charity - and as an added bonus, it got my Dietitian wife to approve of McDonalds.