I found a very, very big database of sounds for characters, objects, spells, ambient and what have you: the sounds of World of Warcraft. Here:
When creating spells, items, creatures, NPC one of the hardest problems is procuring original sounds. Game sound and voices are very important for atmosphere, and they are much easier to vary than visuals. Even if we could redraw areas, with some visuals we are stuck, e.g. character models, and then only sound remains to make an NPC stand out. When "Yes?" isn't enough and "Pleasure to meet ya" doesn't cut it anymore, custom voice-overs are too difficult and time-consuming to get, that's when you want to go and rip some big-studio game for its audio.
