As Per TomLong's Request. 
Game Performance.Average Playtime without a Crash: 3 to 4 hours. or more. Somtimes as much as six, and then I get a memory related crash. Depending on what I am doing, I can go longer.
Average FPS, Cities: Generally around 40-50, depending on area. IC Waterfront during the day is generally about 45.
Average FPS, Other: Capped at 60 by OSR. Regardless of how many folks are around.
System SpecsCPU: AMD Phenom II X4 965 @ 3.4ghz.
GPU ATI HD 4890 1gb RAM
Sound: Sound Blaster Audigy 2 (yes, it has hardware acceleration on the card.)
System RAM: 4gb.
Operating System: XP Pro 64 bit
Load List	Spoiler 	00  Oblivion.esm
01  Francesco's Leveled Creatures-Items Mod.esm
02  Francesco's Optional New Items Add-On.esm
03  Oscuro's_Oblivion_Overhaul.esm  [Version 1.34]
04  Mart's Monster Mod.esm  [Version 3.5.5b4]
05  FCOM_Convergence.esm  [Version 0.9.9MB3]
06  Unofficial Oblivion Patch.esp  [Version 3.2.4]
07  DLCShiveringIsles.esp
08  Unofficial Shivering Isles Patch.esp  [Version 1.4.0]
09  Shivering OOO.esp
0A  MOBS SI.esp  [Version 1.2.2a]
0B  MOBS SI Optional Combat Settings.esp  [Version 1.2.2a]
0C  Francesco's Optional Chance of Stronger Bosses.esp
0D  Francesco's Optional Chance of Stronger Enemies.esp
0E  Francesco's Optional Chance of More Enemies.esp
0F  Francesco's Optional Leveled Guards.esp
10  FCOM_Francescos.esp  [Version 0.9.9]
11  FCOM_FrancescosItemsAddOn.esp  [Version 0.9.9]
12  FCOM_FrancescosNamedBosses.esp  [Version 0.9.9]
13  Lock Bash Omega.esp  [Version 1.5]
14  RAEVWD Cities.esp  [Version 1.7]
15  RAEVWD New Sheoth.esp  [Version 1.5]
16  RAEVWD Imperial City.esp  [Version 1.7]
17  Reznod_Mannequin.esp
18  Harvest[Containers].esp
19  Living Economy - SI.esp
1A  Living Economy - Items.esp
1B  sr_super_hotkeys.esp
1C  DLCHorseArmor.esp
1D  DLCHorseArmor - Unofficial Patch.esp  [Version 1.0.5]
1E  DLCOrrery.esp
1F  DLCOrrery - Unofficial Patch.esp  [Version 1.0.3]
20  DLCSpellTomes.esp
21  DLCSpellTomes - Unofficial Patch.esp  [Version 1.0.1]
22  Bob's Armory Oblivion.esp
23  FCOM_BobsArmory.esp  [Version 0.9.9]
24  Oblivion WarCry EV.esp
25  FCOM_WarCry.esp  [Version 0.9.9MB3]
26  Oscuro's_Oblivion_Overhaul.esp  [Version 1.34]
27  FCOM_Convergence.esp  [Version 0.9.9Mb3]
28  FCOM_RealSwords.esp  [Version 0.9.9]
29  FCOM_DurabilityAndDamage.esp  [Version 0.9.9]
2A  Mart's Monster Mod - No Carrion Rats.esp  [Version 3.5.5b4]
2B  Mart's Monster Mod - No Giants.esp  [Version 3.5.5b4]
2C  Mart's Monster Mod - No Undead Rise.esp  [Version 3.5.5b4]
2D  Mart's Monster Mod - No Slimes.esp  [Version 3.5.5b4]
2E  Mart's Monster Mod - Less Bone Loot.esp  [Version 3.5.5b4]
2F  Mart's Monster Mod - Dungeons of MMM.esp  [Version 3.5.5b4]
30  Mart's Monster Mod - Gems & Gem Dust.esp  [Version 3.5.5b4]
31  Mart's Monster Mod - Hunting & Crafting.esp  [Version 3.5.5b3]
32  FCOM_DiverseGuardUnity.esp  [Version 0.9.9]
33  FCOM_BobsGuardUnity.esp  [Version 0.9.9]
34  FCOM_HungersUnitySI.esp  [Version 0.9.9]
35  FCOM_FriendlierFactions.esp  [Version 0.9.9]
36  FCOM_MoreRandomItems.esp  [Version 0.9.9]
37  DLCBattlehornCastle.esp
38  DLCBattlehornCastle - Unofficial Patch.esp  [Version 1.0.4]
39  BattlehornCastleEnhanced.esp
3A  DLCFrostcrag.esp
3B  DLCFrostcrag - Unofficial Patch.esp  [Version 1.0.4]
3C  Knights.esp
3D  Knights - Unofficial Patch.esp  [Version 1.0.9]
3E  FCOM_Knights.esp  [Version 0.9.9Mb3]
3F  Harvest [Flora].esp  [Version 3.0.0]
40  Harvest [Flora] - Shivering Isles.esp  [Version 3.0.0]
41  Harvest [Flora] - DLCFrostcrag.esp  [Version 3.0.0]
42  RealisticForceMedium.esp
43  RealisticMagicForceMedium.esp
44  sr_spell_deletion.esp
45  Advanced Magecraft.esp
46  Enchantment Enhanced.esp
47  attack and hide medium v2.1.esp
48  StealthOverhaul.esp
49  DD_ProximitySneakPenalty.esp
4A  Duke Patricks Near Miss Arrow Shot Alerts The Target.esp
4B  Duke Patricks - Fresh Kills Now Alert The NPCs.esp
4C  Intelligence Overhaul (No Book Changes).esp
4D  SniperSneakSkillup.esp
4E  Toaster's Legendary Skills.esp  [Version 3.44]
4F  Grandmaster of Alchemy.esp
50  bgMagicEV.esp  [Version 1.7EV]
51  bgMagicSpellTomes_for_WryeBash.esp  [Version 1.68EV]
52  bgMagicEVAddEnVar.esp  [Version 1.68EV]
53  bgMagicEVPaperChase.esp  [Version 1.68EV]
54  SupremeMagicka.esp  [Version 0.90]
55  SM_ShiveringIsles.esp  [Version 0.86]
56  SM_DLCSpellTome.esp  [Version 0.80]
57  SM_OOO.esp  [Version 0.89]
58  SM_MMM.esp  [Version 0.89]
59  SM_EnchantStaff.esp  [Version 0.80]
5A  SM_UnlockSpells.esp  [Version 0.70]
5B  SM_Scrolls.esp  [Version 0.84]
5C  bgMagicEV_Conjuration_for_Supreme_Magicka.esp  [Version 1.5]
5D  Francesco's 10 days respawn time - 1-20 day lenght rescale.esp
5E  bgMagicLightningbolt.esp
5F  X-Ray Detect.esp
60  NO_Recoil_Stagger.esp
61  MouseWheelDisable.esp
62  Bashed Patch, 0.esp
63  JQ&DM-ScriptedBackpacks.esp
64  vjHealthMod.esp  [Version 1]
65  Duke Patricks Script Effect Silencer.esp
Also:
Elys Uncapper
Oblivion Stutter Remover
Conscribe
Pluggy
Fast Exit 2
Large Address Aware patch.
No texture mods as yet. That's next.
 I was originally a morrowind player, so, a fair number of my mods are geared toward giving more of a 'morrowindesque' experience. I am also a big fan of stealth, so, that is why those are there. I have been working on this for a couple years, and the above list is what I consider "standard" now. I just recently built this machine, so, am still adding mods one or two at a time, to fill it out. The vanilla magic system was pretty useless.... so, that got changed as well. At this point, the 'game mechanics' list is fairly complete. I may yet add in a few of the Duke's mods.... they tend to make combat FAR more challenging. (but I am not really a melee kind of guy.) I am waiting for the next version of Unnecessary Violence to come out.
The game runs VERY well, and is quite stable. I had one issue with the Paranoia Quest, (Glarthir) that I have yet to sort out, for now, I am just not dealing with him. I can generally play for as long as I want, and do not crash until such time as I hit the memory cap, and then I am back to the desktop. So far, I have about 76 hours on my current incarnation, and have not experienced any insurmountable problems. Even in cities, during peak crowd times, FPS is smooth, and eminently playable. I have had outdoor encounters with as many as 20 goblins, (or maybe more..... took me a while before I ran out of them....) and combat was smooth, with no stutters, even with six of them 'in my face', and casters standing back pounding me with spells. All in all, I am VERY pleased with the current setup. Textures I think are next. After having a chat with Albertine, and seeing some of his screenies..... (which are awesome by the way) It has become an irresistible urge. I am going to blame that one squarely on him. (her? I don't know....) 
In case you are wondering why the backpacks mod is after the bashed patch.... that's so my backpack actually shows up on my avatar. I use the Unlimited Rings/Amulets feature of Wrye Bash, and that 'breaks' my amulet slot backpack so it doesn't show up. (probably a better way to address that, but, this method works just fine.)