I love numbers. I love lots of numbers listed in one place. I love lots of numbers representing semi-inane information listed in one place. Total damage taken, total healing done, total steps taken, total turns turned,... The list could conceivably be endless! I think tracking however many of these stats would be very intensive to add in the code though, especially in comparison to the "value" it brings to the game-play. It could be tied in with the Menagerie page (which I browse through way more than I care to admit)
I suggest "total number of healing potions the characters were carrying when they died". That's a fun statistic to track.