Keychain - Keeps keys from cluttering your inventory.
This one is pretty pointless if using DarNified UI, which allows one to minimise sections such as that for keys.
Your others are in line enough for me that I will use it as my base below
Let's see. Might as well make up my own list anyway:
Utilities:
http://www.tesnexus.com/downloads/file.php?id=22368: The best mod installation and organisation program for Oblivion. A must for long load orders. Very powerful tool!
http://obse.silverlock.org/: Requirement for many mods, no negative effects, so might as well get it by default.
http://www.tesnexus.com/downloads/file.php?id=27710 (incl for DLCs like Shivering Isles and Kinights...if using those.)
Kivan is working on a new version,
Arthmoor's supplemental are the current latest.
http://www.tesnexus.com/downloads/file.php?id=11280: Improved user interface. You may prefer http://www.tesnexus.com/downloads/file.php?id=10763 instead. This one combines it with Dark UI (colour change) and very minor tweaks.
http://www.tesnexus.com/downloads/file.php?id=12859: Can automatically sell/buy single entire stacks of items or just one with the press of a key. May seem minor but it makes a real difference I think.
http://www.tesnexus.com/downloads/file.php?id=34735: more keys, ability to use various kinds of "combo" keys (armour sets, switching between weapons etc.)
http://www.tesnexus.com/downloads/file.php?id=34735: See more stats in menus
http://www.tesnexus.com/downloads/file.php?id=35969: Numerous map options.
http://www.tesnexus.com/downloads/file.php?id=26389: Change those markers, adds new kinds or markers, and you can even add and alter your own!
http://www.tesnexus.com/downloads/file.php?id=25078: Improves realism, highly configurable too, so adds/changes as much or little as you wish.
http://www.tesnexus.com/downloads/file.php?id=19847: Allows a bunch of stuff, but most importantly; you wont get arrested for grabbing and putting a bottle you knocked over back where it was! (in fact you may well be thanked.)
http://www.tesnexus.com/downloads/file.php?id=2037: Improves the feel of harvesting plants
http://www.tesnexus.com/downloads/file.php?id=37825: Beautiful. (Requires http://www.tesnexus.com/downloads/file.php?id=30054.)
http://www.tesnexus.com/downloads/file.php?id=20053 - Makes more objects visible from a distance.
http://www.tesnexus.com/downloads/file.php?id=35099: Makes caves etc. darker.
You will probably want a torch mods because you will now need torches, for example:
http://www.tesnexus.com/downloads/file.php?id=16282: Drop lit torches to use as light source when it is dark and your hands are full (of sword and shield etc.)
http://www.tesnexus.com/downloads/file.php?id=40098: Same deal, it's new, with a couple of neat additions (might need work still, but it is being actively worked on, which is nice.)
http://www.tesnexus.com/downloads/file.php?id=26524: Gives a lot of NPCs torches, which they use when dark.
http://www.tesnexus.com/downloads/file.php?id=18305: Vastly improves and adds to the weather system, including inside weather sounds etc.
http://www.tesnexus.com/downloads/file.php?id=19628: Lighting windows etc.
http://www.tesnexus.com/downloads/file.php?id=34199: You can look out the windows! These last three compliment each other beautifully!
http://www.tesnexus.com/downloads/file.php?id=21999: Cool more realistic alternative to fast travel.
Some texture overhaul mod
http://www.fileplanet.com/184723/180000/fileinfo/Elder-Scrolls-IV:-Oblivion---Qarl-Texture-Pack-3-Redimized-and-Further-Reduced-OMOD is popular, but can cause a serious FPS hit. Linked is
probably the most FPS friendly version.
http://www.tesnexus.com/downloads/file.php?id=18677: The one I am using right now. There are a number of others; personal taste. Some even prefer having none at all.
http://www.gamesas.com/index.php?/topic/1218260-the-unique-landscapes-project/: Land mass overhauls. Making the world far less repetitive. Link goes to the thread, as it is actually a project including many individual mods.
Body mods:
http://modsreloaded.com/roberts-male-body-5 is the standard for males. He is working on an updated version right now, after a lengthy hiatus. But there are versions available. Linked is one version, but look around, for they body plus armour/clothing for it.
Females have more options:
http://www.tesnexus.com/downloads/file.php?id=24078: One set with a number of options. Linked one includes armour and clothing as well, which you need to keep bodies looking as desired.
TGND Female Body and Clothing Replacer is another option.
Look for "male body" and "female body" or similar, as there are a fair few choices.
http://www.tesnexus.com/downloads/file.php?id=21104 - Check it out to see what it adds etc. Includes optional files to change the looks of NPCs, which with the above body mods makes them look far better. There are a number of other options though.
http://www.tesnexus.com/downloads/file.php?id=35560: Adds, rebalances and re-textures weapons.
http://tesalliance.org/forums/index.php?app=downloads&showfile=797: High resolution of armour and weapons. Note that the linked compilation is not fully up to date; http://www.gamesas.com/index.php?/topic/1179485-relz-insanitys-retexture-releases/
http://www.tesnexus.com/downloads/file.php?id=26634: Increases diversity of critters, and the undead.
http://www.tesnexus.com/downloads/file.php?id=30260: (Combination of Fish, AliveWaters and the Player Fishing mod - found in Optional files of linked page) Makes the underwater environment more interesting and realistic (seaweed, fish etc.)
Large Quest-like mods:
http://www.tesnexus.com/downloads/file.php?id=16316: Novel gameworld spanning mod (stepping stone that teleport you all over the place) Plus more dungeons to explore etc.
http://www.tesnexus.com/downloads/file.php?id=12997: bunch of quests through a new guild.
New towns with quests:
http://www.gamesas.com/index.php?/topic/1178889-relz-arthmoors-villages-of-cyrodiil/: Well worth checking out ( I have them all.)
http://www.tesnexus.com/downloads/file.php?id=35908: Huge open town, plus more smaller ones, with quests within and between them. Includes a number of player homes and quite a decent quest line.
Main Towns (pick only one!):
http://www.tesnexus.com/downloads/file.php?id=33003: Nice re-imaging of the game's main towns: largely based off the original concept art, plus open (no more walled off different world spaces.)
http://www.tesnexus.com/downloads/file.php?id=16360: Original cities opened to the world.
http://www.tesnexus.com/downloads/file.php?id=16513: Another significant change of the cites (includes "open cities" options.)
http://www.tesnexus.com/downloads/file.php?id=35265: Overhaul on gameplay (more challenging to a point, but also more interesting with less levelling irritations)
Companions. If you want a companion:
http://www.tesnexus.com/downloads/file.php?id=28977: Is a nice quality option, But search for companions for all possibilities.