» Wed Oct 06, 2010 3:04 am
GCD and MCA have already been mentioned. Necessities of Morrowind makes the game slightly harder, too.
The MCP can make werewolves tougher, and NPCs in general can use their racial powers (Ancestor Guardian, Adrenaline Rush etc); for the latter, there are also mods with similar effect.
The MPP removes some useless autocalc spells from NPCs.
WGI (Wakim's Game Improvements) gives NPC spellcasters more magicka and better spells.
NPC Magicka Regeneration does what its name indicates.
Morrowind Advanced makes many creatures tougher, and adds higher-leveled (sometimes rescaled or retextured) varietes of them (plus red dragons). Also reduces daedric loot.
Creatures X adds some new critters and tweaks some existing ones.
PTE (Piratelord's Trade Enhancements) makes many things harder; merchants drive harder bargains, and infinite stocks have been replaced by random, slowly respawning stuff.
Srikandis Alchemy (there's a recommended recent "remix" update) is a mixed bag - some things are harder, others easier.
NPC enhanced (there's an MWSE patch for it, so you don't need MWE) improves NPC AI and gives them more potions and marksman weapons.
Taddeus' Balanced Weapons and Armor mostly seem to nerf high-end gear (yours) and beef up low-end gear (that of most NPCs). It does increase weapon reach and speed, though.
GDR (Greater Dwemer Ruins) makes the Main Quest much, much harder. Minions of House Dagoth has probably been incorporated into MCA 6.1, otherwise, it's a good complement.
Pursuit Enhanced is great, but too buggy to recommend.
There are various weather effects (blizzards can freeze you etc) and armor effects (sneak/agility penalties for heavy armour) mods. Also, mods that increase spell and projectile speed, mods that reduce the value of player-made potions (sometimes to 0), mods that make summoned creatures worthless for soultrapping, make certain spell effects unavailable for enchanting/spellmaking etc.
Note: I haven't tested all of the above, and there are some conflicts.