Iron ammunition to range with or runes to mage with.
55 and 61 for Broad bolts
55 for High Level Alchemy
30 and to use a Smoke battlestaff
60 if choosing Melee instead
Fire giants in the Waterfall Dungeon unlocked during the Waterfall Quest drop valuable items like the Rune scimitar. In the Waterfall Dungeon, they may be ranged or maged safely because there is a safespot both behind the rock in the middle of the room and in the doorway as the giants are too large to attack you. Because of this, it is often quite crowded there, but if you can find an empty world to kill them, you can make a decent sum of money. They can also be melee'd with base 60 stats.