When I was really young, I saved my brother from drowning twice, possibly three times (I can't remember if the second scenario occurred twice, or if I'm just remembering the same event twice)
Anyways, the first time, we were in a friend's pool, and we were all playing in the shallow end. He was about 4 or 5, and I was 7 or 8, and he went too near the deep end, and slipped down (the pool had a slope from the shallow to the deep). He couldn't swim very well, and sunk like a rock, but I caught him before he got too far.
The other time, well, let's just say that there was human intervention in his near-drowning. We were only a few years older than the previous time. We were at our grandparents' house, and my two brothers and I were in the lake with a couple of our cousins, who were around the same age as us. As we were playing, the oldest of the cousins - for whatever reason - started to hold that same brother under water. I don't know how long he had been doing it before I noticed, but when I did, I pushed him off and helped my brother up.
So, yeah. Whenever he and I fight, I bring up that I saved his ass twice, and that he owes me