And adding to it, 70+ can be done on Plains of Havoc. Quite interesting hunt in my opinion. Over there you can reach some places with bushes and trees where you will be able to "trap" only one GS attacking you, which will make your fights much more easier. It will be a medium profit and a nice exp, especially if you got some excellent prey bonus. there is a hole there with some Dragons and Dragon Lords that are worth mentioning. Since it is a very diverse hunt (with wyverns, hunters, undeads) all over the place, you will help a lot your Charms counting.
Warlocks and Lost Dwarven are other options once you get over 100 I think, but I'm sincerely clueless on how or when to hunt these things. You will need a really high level to face these monsters as a Free Account Knight.