The Elder Scrolls series has a very strong modding community. The recently-released Morrowind Sounds & Graphics Overhaul v3.0 (FAQ) (trailer) (screenshots) is a mod compilation of 100+ mods (list), which gives a new lease of life to 2002's Game of the Year. It includes a semi-automatic installer (video) (forums) and options for the various mods. A gameplay pack has been in the works for quite a while, but if you want more than cosmetics and don't mind looking around, voila: you may dive in. However, the modding community is at its best in Oblivion. [more inside]
Although the Creation Kit mod development platform for Skyrim (previously) is still a few days from being released, intrepid modders have been working with edited game files to achieve mixed results. One of those results is the "Macho Dragon Mod" (download link). [more inside]
Ever play Morrowind? Did you realise how obscenely gargantuan the backstory and associated literature is? I'm not much of a roleplay geek, but the sheer amount of work to produce this fictious world is kinda hypnotic. And as for this...