Reply here what your favorite sidequest was in the game! No guilds or Civil war.

My favorite That I've played so far would be the Lexicon one in Avanchnzel, Pretty good for a side-quest.

Uhhh, i think the one about sam and the staff was quite interesting. Can;t think of anymore, though i know many side quests are quite interesting

A Night To Remember was fun and unexpected for me.

I can't remember the name of the quest, but the one that involved the burned house in Morthal.

Forbidden Legends. It was a blast and worked well with the way I'm Roleplaying my Altmer Mage.

The one that makes Annekke available

Maybe daedric quests should also be excluded?
I also like Forbidden Legends, although I'm baffled how such an amulet could have given someone such an advantage.

Clavicus Vile's quest tugged at my heart strings, Namira made me literally lol as did A Night to Remember.

Favorite?

Ill met by Moonlight.

Random sidequests?

Dropping the goods off at Hrothgar and then taking them back immediately for no reason.

Agreed.

A night to remember and house of horror(i think that's the name) were quite fun and surprising for me.

Edit, the second one i am thinking of is in Markarth my mistake.

A Return to Your Roots.
Only because it involved running around Blackreach for ages fighting off Falmer and Dwemer automatons.
That quest very nearly killed me, and it did kill Lydia. But the view/scenery and the challenge was worth it.

I haven't done too many, but I liked the qide quest revolving around Namira (with the cannibals in Markarth's Hall of the Dead) and the one with all the nightmares in Dawnstar.