I've just recently wanted to seriously start an Oblivion game (even though I bought it not long after release haha), and this is what I'm using so far, in addition to the ones you already have:
Streamline - will dynamically change draw distances (you can set min/max values it can vary between) to meet a minimum framerate.
OBGEv3 - more effects available (SSAO, Indirect Illumination, HBAO, post-AA, godrays, POM, etc). I'm just using FXAA, godrays, and POM.
Liquid Water - requires OBGEv3. Much better water shader, other water mods just change the color/visibility values.
All Natural (says to not use the whole Natural Environment mod with this one) - more realistic weather system
Immersive Interiors - requires All Natural, shows outside weather conditions from inside
RAEVWD - Really Almost Everything Viewable When Distant, makes unique landmarks stay visible from further away
Animated Window Lighting System - lights up windows+adds smoke to chimneys depending on time of day.
Natural Habitat - part of Natural Environment, just adds bids+insects
FCOM (or just OOO if FCOM's install is too daunting) - lots of people didn't like how enemies level with you in vanilla Oblivion, OOO changes that. FCOM is basically a combination of mods and complicated install process that includes OOO and a bunch of new enemies+loot. http://www.oblivionmodwiki.com/index.php/FCOM
Open Cities Classic - lets you in and out of cities without a loading screen, the doors open up and you walk in.
Jump - reduces jump height quite a bit
Realistic Physics - makes ragdolls fall with more weight+friction
I may have screwed up somewhere along the way tho, because Oblivion crashes on exit every time for me. Hasn't crashed in-game yet tho