Elven armor and glass armor just DO NOT look like anything a thief would wear. It is far too grandiose. You don't have to be a thief to wear light armor, but it doesn't look like what a warrior would wear, either. Kings maybe...at public events.

The armor that looks good, like thief armor, are the Thieves Guild armor and the Nightingale Armor. But those come with their own enchantments, and I want to chose my enchantments. But to choose my own enchantments, I have to make it myself. And Glass armor has the best protection. But it's just so...I don't know know. What's the word here? It's just too much. A thief wouldn't wear ALL OF THAT. It's too busy. Too big maybe. And normal leather armor, that looks ok, can't give as much armor class as Elven or glass armor.

Does anyone know a mod, maybe, that let's you make Nightingale armor, that you can enchant yourself? Or Thieves Guild?

I wonder if the 'Word Shrouded Armor' set can be enchanted? It has none of it's own to begin with.
Dragonscale (Light Dragon Armor) has better stats than Glass as well.

Yeah, I think it's Lost Art of the Blacksmith, or perhaps it was something like Artifact Crafting. Can't remember now, but it did add all those unique armors to black smithing, and they'd come without enchantments.

Alternatively you could easily do it yourself, just open the CK and find the armor set you like, duplicate it, give it a different name and remove the enchantments. You could also then make a smithing recipe for it, or just drop them in the game world.

I think the basic leather armor looks the best out of all the purchasable light armor. I actually hit the max armor rating with enchanting/blacksmithing. Just wear whatever looks good and screw the green-lantern glass armor.

http://skyrim.nexusmods.com/downloads/file.php?id=8003 lets you make unenchanted and enchantable versions of faction gear if you've already joined that faction.

I personally think the Penitus Oculatus Armor and Dragonscale armor are some of the coolest looking armors in the game, but admittedly they aren't really something a thief would wear.

I don't see why the general light armors "need" to be thief-friendly anyway. That's what the guild armors exist for. The idea of a uniform for something like a guild of thieves is silly since the whole point would be not to stand out by wearing a unique suit of armor, but its there because some of the other light armor doesn't look "thiefy" enough.

I also don't see how Elven and Glass look unfitting for a warrior. They're fancy looking I guess, but who says warriors have to wear drab armor? Especially since in the ES universe the materials themselves are colored that way, its not like the armor is painted bright green specifically to look showy, the glass material itself is that color.

My only complaint about any of the light armors is that Glass looks a bit too bulky to be light armor. I guess the material is probably very light, so the bulk isn't a big issue as far as weight goes, it just doesn't look easy to move around in.