What are some of the most memorable or impactful side quests in RPGs?

[1stop]

The side quests have become such an interesting memory that they frame how you see these worlds and characters. I have had my own fair share of some unforgettable side quests. What are the great ones you have encouraged?

[Demonskeith]

I know early final fantasy games had side quests that would really pull at your heart strings.