I need a new jungler, and I want one that's decently snowbally, fun, and can counter jungle fairly safely.

Which of the two is better to play? (ranked)

Shyvana, IMO, but fun is subjective.

Heracin if you play with mates and they charge with you.
Shyvana if you are going for solo queue and need to be doing most without relying to much on teammates.

Ah sry. didnt read the last. Heracin cant counterjungle and is actually pretty vulnerable early. Then better shivana (in a 5v5 premade heracin is far better though!)