Side quests have been a thing in video games as long as there have been games longer than three hours. They're the little stories within the larger narrative that grant you rewards the main story doesn't, flesh out the world a little by showing what people NOT associated with the quest to slay the Ancient Dark Lord Ticklefloof are up to, and establish secondary characters you otherwise would not have come across.
But the main story beckons all the same, so ideally you shouldn't want to make the side content more interesting or more engaging than the actual main game itself.
These ten games should definitely have remembered that part.
A main story can feel like you're on a railroad at times, so it's usually the player's choice to engage with content beyond the primary serving. Or maybe the main story is just kinda bad and the side quest where you sit and watch paint dry is a million times better in comparison.
10. The Lover's Quest - The Legend Of Zelda: Majora's Mask
This one is at the bottom due to the very nature of the story of Majora's Mask tying both the main and side quests together. Because of the time management system, if you want to do side quests, you have to wait until the right time and the right day for them to become available, and well, you gotta pass that time somehow so main quest it is.
But one particular side quest was so engaging, so compelling, and so intimate that you suddenly ceased caring about the giant moon about to crash down on your head until that very quest reminded you of the impending apocalypse. And that's The Lover's Quest.
If you follow a lot of gaming channels on YouTube, then you're probably sick to death of people gushing about it, but the reason for that is because it's the perfect complement to the main story of the game. Other side quests are just fine, some are even great on their own, but the quest to reunite Anju and Kafei, the trials to get Kafei his body back, and of course, the waiting in Anju's room on the final hour of the final day, eyeing the clock tick down and legit thinking that he won't be coming, only for him to barge in to marry his love at the literal last moment, gives this grand adventure a much needed intimate touch.