I just reinstalled this game, and here's a rough rundown of what I'm running:
Beautiful People -Adds a bunch of new hair meshes / eye designes / custom races, plus makes in game characters look better
Beaming Sunglare - Just what it says, a better bloom effect for sunlight
Bobs Armory - More weapons and armors
Color Map Mod - Replaces the in game map with a color version
Harvest Containers - Changes all the containers (chests, barrals, dressers, ect.) so they have a different graphic effect once opened. There is a similar one in the Oscuro mod that does the same with all vegetation.
House Map Markers -Only lets you fast travel to houses once you've purchased them
Leviathan Soulgems - Replaces the soulgems with better looking ones
Loading Screens - Adds a lot more cool loading screens.
Marts Monster Mod - Adds a bunch of different monsters + a few other cool tweaks
Natural Enviroments - Makes all the trees larger and more lush, adds really cool ambient creatures to the wilderness (rabbits, birds, ect.), and makes the nights a lot darker. Also adds seasonal weather paterns, and better weather effects. This is probably the single non-gameplay mod ever because it makes the game look so much cooler.
Oscuros Oblivion Overhaul - Tons of changes to the gameplay. Highly recommended
Quarls (sp?) Texture pack - Replaces all the ingame textures with much better high res ones. It takes more memory, but if you have a fast PC (8800 GTS/GT/GTX, and a decent CPU) you probably won't notice the difference. This one is really great because of how much better the game looks.
Most mods are going to be compatible with each other, just don't install multiple mods that perform the same function. I.e. two mods that change archery are going to be redundent and won't necessarily break the game, but you probably wont get the result you're looking for.
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