My Dad is alive purely because someone signed an organ donor card and gave him a heart, and we will always be incredibly grateful both to the donor and that the donor's family upheld his decision and despite what must have been terrible grief still allowed the hospital to use his organs.
Mt Dad was always slim, reasonably fit and healthy, but he caught a virus which left scar tissue in the muscle around his heart which slowly caused it to die.
Six months after he caught the virus, on Christmas Eve, we were told to say goodbye to him as he wouldn't make it to New Year - he was emaciated and weak and could barely raise his head. This was at the age of 60. My Mum, sisters and brother and myself (despite being 3 months pregnant) stayed at his bedside around the clock, and somehow he made it to New Year and got just a little bit stronger.
A few days later, the call about a viable and tissue-matched heart came through, and within hours he was in theatres being operated on. We had to say goodbye (again) before he went in as there was no guarantee he'd get through the op, but he did, and quickly already looked so much stronger. His cheeks looked rosy again, and he was sitting up within a few hours.
That was over ten years ago. He not only saw his first grandchild, but five more (so far). Him and his gentle humour and patience are still around, and we are all so happy to still have him.
He's just one of the people saved by the same donor. I think in all seven or eight of his organs were used, so I very much suspect my family wasn't the only one touched by this generous act. Of course, we all carry our donor cards and would do the same thing to pass it forward if we ever had the chance because we know how much it would mean to so many people.