I'll list the ones I know of. If you want more info on one of them, let me know.

1) Catching thrown items.

2) Worker 8 in Nelveska Temple

3) Move-Find and Brave

4) Large monsters and steep terrain

5) Defeating Velius

6) Learning the Ultima spell

7) Learning Zodiac summon

8) Teaching Zodiac to other units

9) Monsters worth poaching

I'm leaving out the item duplication trick and proposition issues, since those don't involve battles directly.