List O' Oblivion Modlists
With Oblivion Remastered out, it may seem strange to still be modding the original Oblivion. However, there are a few reasons to do so. First, OG Oblivion has much lower system requirements, as opposed to the very demanding Remaster. Second, the modding scene is much more mature for the original game. There are many more mods available, and with a level of features that can't be replicated yet in the Remaster. This may change with time, but probably not for a long while if ever.
Want to mod the original Oblivion, but don't know where to start? Just want some curation from the vast sea of mods out there? Here I've compiled a list of lists, ranging from Vanilla+ and QoL to graphics, to themed and personal modlists, for modern modded Oblivion.
Some of these lists are manual, meaning you'll need to install the mods yourself following the instructions in a guide. Others use Wabbajack, an automated modlist downloader, though they still generally have some pre- and post-setup instructions. In either case, a Nexus Mods Premium subscription will cut your installation time substantially.



Beginner/Vanilla+
Through the Valleys -- A modlist that aims to be vanilla+ and beginner friendly, tweaking the game without adding a ton of new items or overhauls.
Last Seed -- Wabbajack list specifically targeting Skyrim players unfamiliar with Oblivion.



Graphics
Heartland Redux -- Wabbajack install that focuses on comprehensively overhauling Oblivion's graphics.



Personal
My Mod Recs -- Mods I use and recommend. Skews more towards smaller/less popular mods not featured in other modlists.
Oblivion Comprehensive Modding Guide -- Large curated list of mods, meant for either beginners or experienced modders. Several options suggested for some areas depending on taste.
A Painted World -- Wabbajack modlist that overhauls Oblivion with a lot of modernized features and RPG mechanics.
Reign of the Septims -- Comprehensive modlist that aims for stability and modern improvements. Has a couple different flavors, here's a version that uses Oscuro's Oblivion Overhaul, if you're interested in that mod.



Themed
GlitterGear's Blog -- Contains a number of themed modlists, from dungeon mods, main quest mods, thievery mods and more.
Exhaustive list of new content/quest/dungeon mods -- Reddit post with recommendations. Links to even more recs in the comments!
Extremely Subjective Oblivion Quest & Adventure Mod List -- Reviews from one perspective of a number of quest/adventure mods. Good both for mods to check out and ones to stay far away from.