Several of my mods exhibit recurring themes. This may be variants of the same idea in multiple games of the TES series, or a series of mods that do similar things for the one game. Like the Ouroboros, they feed on themselves, even cycling back in time to earlier games, or in the case of ESO, a later game set in an earlier time.
My first mod (for Oblivion) was the Bear Rider of the Rumple Mod. She has been recreated for Skyrim, and also appears as one of my ESO characters, where you can't have mods. Diablita and Angeline started in Oblivion, too, and were re-made for Morrowind, and then Skyrim. The Hearthfires series of mods depend on the Hearthfires DLC for Skyrim, so they're all for that game.
Another recurring theme is mods getting started, but not finished.
The inspiration
Oblivion version
Skyrim version
ESO version
Unna was the first Bear Rider, and the only one in the initial release, but was soon joined by Svana, Pala, and Ystrel. The mod then expanded with the Lodge and recruiting Captain Gudrun, and the merge with the Gweden Brothel mod added Uzgash.
A mod for Skyrim was started, and a new lodge built near the border with Cyrodiil. Similar characters were installed, and a quest made to join the Riders and get your own Bear to ride. Getting additional Rider NPC's to patrol was where I ran into show-stopping issues, as matching rider and mount was nasty.
It was a long time before my ESO Nord was able to purchase a white bear to ride, but there's an Unna there now, too.
No Morrowind version, because you can't ride anything there.
First created for Oblivion
Then for Morrowind
and now Skyrim
Wings now optional.
Diablita and Angeline are the classic "shoulder voices" but full-sized, and more likely to sit on your face than your shoulders. They were intended to be a double-value version of Vilja, with comments and dialog for all occasions, but the logic grew too complex, and the mod never got to a state I was happy with releasing.
A Morrowind version was necessarily simpler, with that game's lack of dialog, riding, etc. that were a pain to coordinate (the three-body problem). That one was ready to ship when the Nexus pulled its takeover stunt, and all my mods were pulled before this one even got there.
A Skyrim version of the characters was inevitable, but body physics, voiced dialogue etc. were beyond me at the time. Now they are getting closer, and a mod might emerge.
Oblivion first, as usual
Daggerfall only had 2D sprites
Skyrim LE got a player outfit
Skyrim SE put it on Serana
Morrowind got one, too
Vampirella has been a character I've played whenever a reasonable vampire character was called for. It has meant making a new outfit for each game, but she's worth it. For Skyrim SE, I put the outfit on Serana, who looks good in it.
Skyrim was the only game for which a mod was ever released, and there was one for LE (player outfit) and one for SE, on Serana. The assets for the other games are available, but not packaged for installation. In the case of Daggerfall, the tools to do that may not work any more.
Orc HF wise woman Yarob
Dremora HF housecarl
Forsworn HF hagraven chick Drusilla
Conina the Hairdresser - Player as Rincewind
The Hearthfires houses (offical ones) are all Nord arhitecture, with much of the house the same. The player got to choose the wings, but the choices were the same at each site. I wanted a lot more variety, so mods ensued.
The Orc Stronghold was first, as my character at the time was a female Orc who felt that the male-led strongholds were not to her taste. Then I played an Argonian, who wanted at least the entrance to be underwater. The Khajiit wanted to live in a wagon, but he got a workshop to go with it. The Bosmer got a cave, as there aren't any trees large enough to hollow out. The Dremora had to remake a Nordic tower into a liveable home, but he got a Dremora housecarl for his trouble. For Bretons, a Hagraven's lair was transformed in the Forsworn edition.
Several of these homes come with a housecarl, or similar potential follower.
I also count Conina as one of these, as it lets you build her Salon in the starter home, instead of making it a boring entryway.
Skyrim mods list, includes some add-ons that go with these, such as an Orc child, and a resources tweak.