I figured it would be neat to keep track of statistics that you rack up in battle. Things like, the most damage dealt by each character in a single attack, or the total amount of damage that character has dealt or taken.
Per character:
Max damage dealt in one attack (whole-party spells are cumulative)
Total damage dealt
Total damage received
Total damage absorbed
Total health restored (include potions)
Enemies defeated
Number of deaths (stone counts)
Include totals/maxes for the entire party for all of the above.
Total steps taken (on foot, by sea, by air, by river, in towns, in dungeons)
Treasure chests collected (%)
Battles fought (land/sea/river/dungeon)
Total gold earned (won in battle, found in chests, by selling items)
Total gold spent
Total consumables used (potions, tents, arrows, whatever -- could even list them individually)
Game saves
What else?