I played all 14 Quests "vanilla" as a child, but--let's face it--these quests are for children. However, when our group began this task of tackling all 66 quests, I was the only one of us who had ever played before, so we probably did the first three or four quests straight out of the book. Then I began adding traps and abilities to monsters to spice up the rest. Once we got to Kellar's Keep, though, the book had become just a guide. Chaos Dwarves and a Halfling Hero were added to Kellar's Keep, for instance, and Skavens and a Skaven Necromancer Hero to Return of the Witch Lord. We also didn't want to sit through the solo quests in Frozen Horror and Mage of the Mirror, so I added subplot quests featuring new Heroes (Barbarian children, Lesser Elf Heroes) as a kind of prequel to the main storylines (which I also altered). Along the way, I've been creating my own monster cards, equipment cards, artifacts, spells, and we've added all the colored dice we can (black and blue, then green, then orange and purple).
I have faithful records of all of this thanks to HeroScribe, but I'll stop short of posting unless people would like to see specific quests or items. I will pass along, however, the sole video our Wizard created of one of the last quests in the Frozen Horror quest pack:
http://youtu.be/hSHEZZDBPHg It gives a pretty good look at the game nights themselves, complete with original scripts and sound effects.
I look forward to more conversations!