I recommend setting some prizes and let the winner pick first, second place pick second and so on to let best places get what they want instead of having to aim for a lower score.
Suggestions:
1. Semi Rare/ Rare creatures for combat, particularly I would like to see GG Drach and the LR archer more available through HCs.
2. A Wishpoint is always a good choice.
3. Items with spells (rechargable)
4. Good amount of gold, like 30gc, 50gc, etc.
5. Fully tokening of X creatures or Y tokens applied to creatures of choice.