Current Top 10 Oblivion Mods
For those of us playing on the PC, the Oblivion experience has only gotten better since launch. Planet Elder Scrolls has a short blurb on ten promising mods already released by the community. The top two have been running on my system for slightly over a week now; I highly recommend BTMod (mentioned by Tycho last week) and Natural Environments.
Oscuro's Oblivion Overhaul
Does a bunch of good stuff, but most importantly it gets rid of that stupid level scaling thing.
I've been involved in some debates over that, and I still maintain its dumb, mostly as it provides no sense of accomplishment to leveling or getting better items or anything.