tinyE: What exactly did Hellfire have exactly?
There was the Monk, who I did like, though I remember his specialty was being unarmed which kind of killed the thrill of finding loot. :P
What was the other class? And what sorts of weapons were added?
LOD was so much more because it totally changed the game. The added specialty items like the heads for the Necromancer and the special helms for the Barbarian could completely change how you built your character and played the game.
I don't remember anything like that in Hellfire.
Monk was the only class added in Hellfire. Here is the wiki which shows most of the additions