If you can see clearly in caves, forts, ruins, etc. it is quite possible that you monitor/television is improperly calibrated.

Well the vast, vast majority seem to think this is a problem, so maybe your monitor/television is just incredibly dim.

but then you could always just use a lighting spell and your darkness would be pointless....
I dont think making things even darker will add anything to the game, because of the 2 lighting spells. Just add a little darkness to make it feel real

One thing that has really bugged me throughout the series (granted, Oblivion improved it, but nowhere near enough) is the light levels. They have always been far too bright. I've never once needed to carry a torch. Not once. Ever. I would like to suggest that we have certain caves with a 100% darkness, and no light sources. I think this would make rather interesting gameplay. In http://planetelderscrolls.gamespy.com/View.php?view=Mods.Detail&id=8367 mod, I created an ancestral tomb with 0% light, and running around with the faint light of my torch was great, if I do say so myself.

And for the caves/ruins that do have light sources, I would like to see them stand out more. Create "patches" of dark, with well placed torches. Let enemies hide in the shadows. Let ME hide in the shadows. Let me remove torches with telekenises or a Thief inspired arrow, to move along the path undetected (other than a few NPC's made suspicious).

Create shady taverns and prisons with low lighting. This could also be introduced in castles. Have well lit throne rooms, but have corridors sneak in-able.

I also enjoyed the light effects that came from Morrowind's plantlife. And I believe the wilderness should be significantly darker. When I'm not in a town/fort/camp, I should struggle to see without a torch. I would like to be ambushed by bandits preying on the roads. Forget the chameleon effects of sneaking we've saw suggested, this, I believe, could vastly improve the abilities of NPC's sneaking.

I once installed "The Light Mod" for Morrowind. It has never left my mod list. Global lighting is reduced, light sources give off more light, I was given a Night Eye effect and greatly reduced sneak for carrying a light source and it improved my gameplay a lot.

I have always believed that lighting is the most important thing for visual quality. Without it, the game seems rather bland and uninteresting. Of course, players that dislike challenge always have the option to turn the brightness up and see everything always.

i agree, but i did use torches sometimes since i turned the darkness down

I doubt that "vast, vast majority seem to think this is a problem". These darker nights and pitch black mods seem to be more of a niche than anything.

The few mods I've used that don't include any lighting in their dungeons tend to just be annoying. If they are going to make these beautiful looking dungeons, I want to see them. Otherwise you end up just walking around with Nighteye on all the time making the darkness pointless in the first place.