Skyrim is such a massive open world that it takes an eternity to complete every little side thing it has to offer. Not to mention, the main plot can only be done so many times before the player is sick of hearing Delphine snip at them for not killing Paarthurnax, deal with the Stormcloaks and Legion fighting each other instead of the Thalmor, or chasing down Alduin across time and space.
The good news is that there are so many factions, radiant quests, and general other activities to keep the player's attention for hours, regardless of if mods are installed or not.
10 Becoming The Listener Of The Dark Brotherhood
It might not be as rich as its Oblivion predecessor, but the Dark Brotherhood faction questline is one of Skyrim's best. It has the player stealing a hit from a run-down and failing Dark Brotherhood and then working through the ranks until Cicero and the Night Mother arrive, making it clear that the Wrath of Sithis is about to descend upon the Sanctuary for them disregarding the tenets.
There is also the option to take down the Dark Brotherhood instead- if they attack and kill Astrid during the recruitment process. But that half of the potential questline is less rich and interesting than the primary quest is, where there are some of the most interesting NPCs lurking.
9 The Dragonborn DLC In Its Entirety
The Dragonborn DLC sends the dragonborn to Solstheim where they will encounter a harsh environment graciously "gifted" to the Dunmer refugees from Red Mountain's eruption. It is full of new shouts, dragons, and even the ability to tame the beasts which makes for a great time.
It also brings in more Skyrim history and lore by having the player square up against the first Dragonborn, the former Dragon Priest Miraak. An interesting point is depending on whether or not the main storyline has been completed of the base game will depend on how Miraak addresses the player.
8 Collecting The Stones Of Barenziah
Most of the time, fetch quests are annoying and just constantly rank the lowest on player's lists. However, collecting the Stones of Barenziah is more of a collection-based fetch quest and gets the player to really explore the vastness of Skyrim doing most of the major quests in order to find them all.
It's a fun, long-running collection where finding them is like going on a little treasure hunt and finally collecting all of them brings about an intense sense of pride.
7 Exposing Mercer Frey In The Thieves Guild
The Thieves Guild really takes the cake as far as faction quests in Skyrim. It couples the Daedric Prince Nocturnal's quests with a story of traitorous espionage, sending the player through Skyrim's underground where Mercer Frey has been siphoning his own faction's money out from underneath them.
His greed has angered Nocturnal, and it's up to the player, Brynjolf, and Karliah to revive the order of the Nightengales and take Mercer Frey down, bringing back the guild to a profitable position. It is one of the best moneymakers in the game too and offers many radiant quests that can be completed ad infinitum. It even gives access to plenty of fences to take all the player's hot goods.
6 Following The Companions & Becoming A Werewolf
When starting up a Skyrim game, the most important thing on most players' minds is deciding if they are going to end up being a werewolf or a vampire in that run. The Companions are a guild of fighters with a bit of lycanthropy thrown in, making it one of the easiest places to contract the disease.
It's also got a questline that is definitely not for more squishy mage types, with some actually difficult missions the player is going to get tossed into in order to gain favor and prove themselves as one of the pack.
5 Getting Into Trouble With Sam Guevenne
The Daedric Princes have been deific staples in The Elder Scrolls and often have little side quests where the player can obtain extremely powerful loot from. Sanguine often has some of the most hilarious quests, and his quests in Skyrim are no different.
First off, the player has to go to the bar they were closest to when they reach level 14 and meet up with a drunkard Sam Guevenne. He will challenge them to a drinking contest, and then the player has to spend the whole next day retracing what they did when under the influence of the Prince of Debauchery, all the way until meeting up with him having a party and giving the player one awesome staff.
4 Hunting Dragons Is Just A Fun Time
Occasionally, dragons will spawn and it is up to the Dragonborn to take them down or risk the villages being burned to the ground. They have a higher chance of spawning with a lot of fast travel too, almost like a punishment for not just walking places.
They are all fun fights and tend to scale with the player's level, unless of course there are mods installed to make them more dangerous. Once they're killed, the Dragonborn absorbs their power and it helps bump up their abilities.
3 Joining The Dawnguard Or Siding With The Volkihar Vampire Clan
The Dawnguard DLC is the epitome of a good, complicated one. In it, the player gets to make a ton of choices, from joining the Dawnguard in an attempt to eradicate the Vampires plaguing Skyrim, to joining the ancient clan of them and becoming a Vampire Lord in their own right. After that point, the player is also given the opportunity to decide to bring about an eternal night or to stop centuries of madness.
What is really fun is that should the player decide to bring about an eternal night, any vampire abilities are not adjusted for daylight hours. Canon vampire NPCs such as the Dark Brotherhood's Babette will be found wandering around, which is a fun addition in and of itself.
2 Meeting Up With Sheogorath On Vacation
One of the other most interesting Daedric Princes is Sheogorath, the Lord of Madness. He has been on vacation for a handful of years, sitting in the mind of the late Emperor Pelagius Septim III. Dervenin, one of his staff, has been trying to get him to come back to the Shivering Isles and stop the war between Dementia and Mania due to the Flame of Agnon dying out, and it's up to the player to convince him to do so.
What is truly amusing about this particular line of quests is that canonically, the protagonist of the previous game canonically ends up taking Sheogorath's place at the end of the Shivering Isles DLC. So they are just continuing their sidequests and avoiding the main plot that the player themselves was probably doing at the time of doing their quest anyway.
1 Unraveling The Mysteries At The College Of Winterhold
The College of Winterhold is extremely magic-focused, but even players who are less fond of Skyrim's magic mechanics can have a place unraveling the coup going on within the structure's walls.
Turns out there has been some extreme manipulation going on and the archeological efforts the College is putting forth are uncovering some less than savory characters, which the player will inevitably have to destroy in order to save the place. In the end, they end up as the Headmaster, despite the fact they technically spent very little time in their own classes.